Kittysplit Blog

Chegaram as contas - suas Kitties seguras e sincronizadas

Thu, 23 Apr 2026 00:00:00 +0000

As contas chegaram. Faça login no Kittysplit (web, iOS ou Android) e todas as suas Kitties vão junto com você. É a nossa maior novidade em muito tempo, e é totalmente opcional.

Por que contas?

Durante muito tempo, o Kittysplit funcionou sem conta nenhuma, e isso foi de propósito. Sem conta, não tem cadastro, não tem senha para lembrar e nenhum dado pessoal é coletado. Naquela época a gente também ainda não tinha apps para celular, então trocar de aparelho não era um problema tão grande.

Só que as contas foram o pedido número 1 na nossa pesquisa, e a gente ouviu isso muitas vezes desde que os apps foram lançados no ano passado. Então, finalmente, aqui estão elas! Lançar contas nem é tão difícil. O interessante é mantê-las opcionais. Foi preciso planejar tudo com muito cuidado para que uma Kitty funcione do mesmo jeito, com ou sem login.

Suas Kitties em todos os aparelhos

Faça login na web ou no celular e você vai encontrar as mesmas Kitties em todo lugar. Chega de garimpar conversas antigas atrás do link. Celular novo? Trocou de navegador? É só fazer login e continuar de onde parou.


Fazer login ou se cadastrar	Seu perfil

Kitties mais seguras

Se você criar uma Kitty depois de fazer login, ela é sua. Só você pode editá-la ou excluí-la, então nada importante some por acidente. Seus amigos continuam podendo adicionar despesas e acertar as contas como antes. Para eles, nada muda.

Seus amigos não precisam de conta

As contas são opcionais, e vão continuar sendo. Convide as pessoas do jeito de sempre: mande o link e elas já podem começar a dividir. Sem cadastro, sem complicação. Esse continua sendo o coração do Kittysplit.

Em breve: fotos de perfil

A próxima novidade são as fotos de perfil: envie uma foto legal para aparecer como mais do que só um nome nas Kitties dos seus amigos. E ainda temos mais algumas ideias só para quem tem conta a caminho.

Divirta-se dividindo! 🐱✨

Tem sugestões ou ideias? Fale com a gente no X, Bluesky, Instagram ou mande um e-mail para info[at]kittysplit.com

Anexos nas despesas - coloque fotos nas suas despesas

Thu, 12 Mar 2026 00:00:00 +0000

Agora o Kittysplit tem anexos nas despesas! Você pode anexar até 3 imagens a qualquer despesa da sua Kitty. Esse é um recurso da Super Kitty, então você vai precisar atualizar sua Kitty para usá-lo.

O que há de novo?

Toda despesa agora pode ter fotos anexadas. Tire uma foto do comprovante, da conta do restaurante ou do que quer que vocês estejam dividindo, e ela fica ali junto com a despesa para todo mundo ver.

Você pode adicionar até 3 imagens por despesa, o que deve resolver a maioria das situações. Pense em comprovantes, notas de hotel, ingressos de show ou só uma foto do que você comprou, para o pessoal saber o que está rachando.

Chega de vasculhar a galeria semanas depois atrás daquele comprovante. Anexe na hora de adicionar a despesa e pronto.

Como funciona

Quando você adiciona ou edita uma despesa, aparece uma opção para anexar imagens. Escolha uma da sua galeria. Se precisar trocar alguma depois, é só remover e adicionar outra.

Experimente

Atualize para uma Super Kitty e anexe fotos na sua próxima despesa. Só isso!

Divirta-se dividindo! 🐱✨

Tem sugestões ou ideias? Fale com a gente no X, Bluesky, Instagram ou mande um e-mail para info[at]kittysplit.com

Chegaram as categorias de despesas - mais clareza nas suas Kitties

Wed, 11 Feb 2026 00:00:00 +0000

Temos uma novidade bem útil no Kittysplit: categorias de despesas! A partir de hoje, você pode organizar cada despesa e receita das suas Kitties em categorias e ver com mais clareza para onde o dinheiro está indo.


Adicionar despesa	Filtrar por categoria

O que há de novo?

Toda despesa ou receita que você adiciona à sua Kitty agora pode ficar em uma de 12 categorias:

Aluguel e casa - aluguel, financiamento, seguro residencial e o básico da casa
Alojamento - hotéis, casas de temporada e estadias curtas
Alimentação e compras - idas ao supermercado e comida para casa
Restaurantes e bebidas - restaurantes, bares, cafés e comida para viagem
Transporte - combustível, transporte público, apps de corrida e aluguel de carro
Serviços e comunicações - contas de luz, água, internet e telefone
Saúde - despesas médicas, farmácia e plano de saúde
Lazer e atividades - entretenimento, passeios, shows e eventos
Compras e equipamento - roupas, eletrônicos e compras em geral
Bem-estar e cuidados pessoais - academia, spa, beleza e autocuidado
Finanças e taxas - tarifas bancárias, taxas de serviço e outros custos financeiros
Diversos - tudo o que não se encaixa em outro lugar

Cada categoria tem sua própria cor, então dá para perceber padrões só de bater o olho.

Filtre suas despesas

O primeiro recurso que lançamos junto com as categorias é o filtro de despesas. Agora você pode filtrar a lista de despesas por categoria para encontrar rapidinho:

Todos os gastos com restaurantes da viagem em grupo
As compras de supermercado do apartamento que vocês dividem
Os custos de transporte da sua viagem de carro
Qualquer categoria que você queira revisar

Assim fica muito fácil responder perguntas como “Quanto a gente gastou com comida?” ou “Quanto custou a hospedagem nas férias?”

O que vem por aí?

Isso é só o começo. Já estamos trabalhando nos próximos recursos para você tirar ainda mais proveito das despesas com categoria:

Comparação mês a mês

Acompanhe como os gastos de cada categoria mudam ao longo do tempo. Veja se a conta do supermercado está subindo aos poucos ou se vocês estão gastando menos com restaurantes do que no mês passado.

Análise de tendências

Descubra padrões e tendências de gastos ao longo de semanas, meses ou até anos. Perfeito para quem divide a casa e quer organizar melhor o orçamento.

Relatórios visuais

Gráficos bonitos mostrando como as despesas se dividem por categoria. Gráficos de pizza para a distribuição geral, gráficos de barras para comparar categorias e linhas do tempo para ver como os gastos evoluem.

Por que categorias fazem diferença

Seja dividindo apartamento com amigos ou planejando uma viagem em grupo, as categorias ajudam você a:

Entender seus padrões de gastos - veja para onde o dinheiro do grupo vai de verdade
Planejar melhor - use os dados de antes para fazer o orçamento de eventos parecidos no futuro
Manter tudo transparente - todo mundo no grupo vê quanto foi para cada categoria

Comece hoje mesmo

As categorias já estão disponíveis na versão mais recente do Kittysplit. É só adicionar ou editar uma despesa e você vai ver a opção de escolher uma categoria. Simples assim!

Como sempre, adoraríamos ouvir o que você acha e suas sugestões para as próximas melhorias.

Divirta-se dividindo! 🐱✨

Tem ideias para deixar as categorias ainda melhores para o seu caso? Fale com a gente no X, Bluesky, Instagram ou mande um e-mail para info[at]kittysplit.com

Nova visão geral e avatares de gato

Tue, 09 Dec 2025 00:00:00 +0000

Bem a tempo do Natal de 2025, os apps do Kittysplit ganham uma atualização (v1.3) com duas melhorias que a gente queria fazer há um tempinho:

Uma visão geral redesenhada, que mostra o que importa sem afogar você em números
Avatares de gato, para um visual mais simpático e divertido

Visão geral: antes e depois

A visão geral é a primeira coisa que você vê ao abrir uma Kitty. Nós a reformulamos para responder rápido às suas principais perguntas: quanto custou o evento no total? Quem deve quanto? No geral, tentamos dar mais estrutura a tudo com a ajuda dos Cards do Material Design. Em algumas partes, isso vai até além da visão geral.


Visão geral da Kitty - antes	Visão geral da Kitty - depois


Visão geral da Kitty - depois (modo escuro)	Gerenciar participantes - depois (modo escuro)

Um avatar de gato para cada participante

Em cada Kitty, todo participante agora ganha um avatar de gato só seu. Sim, combina com o nome Kittysplit, mas também tem motivos práticos.

Elementos visuais ajudam você a passar os olhos pelas informações mais rápido do que só com texto. Os gatos ajudam a:

Deixar o app com menos cara de planilha
Reconhecer os participantes em grupos maiores
Ver quem pagou o quê ao rolar a lista de despesas


Avatares de gato (exemplo)

O que não mudou

Não precisa de cadastro
Funciona na web, no iOS e no Android
Cálculo inteligente das dívidas
Grátis na maioria dos recursos

Baixe a atualização

Quem usa o celular recebe a atualização pela App Store ou pelo Google Play.

Conte para a gente o que você achou pelo e-mail info[at]kittysplit.com ou pelo botão de feedback.

Kittysplit's RevenueCat Shipaton 2025 Story

Tue, 30 Sep 2025 00:00:00 +0000

We’re excited to share our story for the RevenueCat Shipaton 2025! As part of this fun hackathon, we finally took the leap and shipped our long-awaited Android and iOS apps for Kittysplit. The Shipaton challenged us to not just build something new, but to actually ship it and that’s exactly what we needed to push our mobile apps from “someday” to “today.” Below is the story we submitted for the hackathon, chronicling our journey from a simple side project born during a ski trip to launching our mobile apps.

Kittysplit: Easy splitting of group expenses

Inspiration

Kittysplit started as a side project born from a real problem we faced during a ski trip with friends years ago. We were struggling to split our expenses fairly and efficiently. Excel felt clunky and overcomplicated for what should be a simple task. When we couldn’t find an existing tool that was truly easy to use, we decided to build our own.

What began as a web-only solution has grown organically over the years. We’ve continuously improved the platform based on constant feedback from our users, who have been incredibly helpful in shaping what Kittysplit has become today. As our user base grew, one request kept coming up:

“When will you have mobile apps?”

We started working on the apps when we had time, but participating in this hackathon gave us the final push to finish and ship them to the app stores.

What it does

Kittysplit solves one problem really well: making group expense splitting effortless. Whether you’re on vacation with friends, sharing household costs with roommates, or organizing a group dinner, our app provides the simplest way to calculate who owes what to whom. No overcomplicated features, no confusing interfaces: just straightforward expense splitting that anyone can understand.

How we built it

The journey to mobile started with building an API to integrate with our existing web application. Our initial plan was ambitious: use Kotlin Multiplatform for shared business logic, networking, local storage, and calculations, and build two separate user interfaces: a Jetpack Compose UI for Android, and a native SwiftUI frontend for iOS.

Since we already had Android development experience, we began with the Android app and built the multiplatform part and the Compose UI for Android. We took great care to keep our client side business logic fully separate from the UI implementation by using ViewModels with StateFlow in Kotlin multiplatform. This allowed us to reuse all business logic for our iOS app. For the multiplatform payment system integration, we used RevenueCat - it turns out that Kittysplit and RevenueCat are a purrr-fect combination!

Then we started working on the SwiftUI client. Initially, it seemed quite straightforward and using our KMP ViewModels from SwiftUI code worked really well. However during the process, it turned out to be a lot more work than expected. We also realized that building our UI in Compose was much easier than in SwiftUI, and that Compose Multiplatform would save us significant development time and effort. This pivot allowed us to share not just the business logic, but also most of the UI code between platforms.

Challenges we ran into

Most of our challenges were product-focused rather than technical. The biggest question was how to translate the simple, intuitive flows that work well on the web into mobile app experiences. We spent considerable time ensuring that the mobile version maintained the same simplicity that makes our web app successful. Keeping the product simple sounds easy, but the big challenge is hiding the technical and mathematical complexity from the user and make it all work intuitively.

On the technical side, we took great care to keep our client side business logic separate from the UI implementation by using ViewModels in Kotlin multiplatform. The main challenge was realizing that building and maintaining a separate iOS frontend in SwiftUI besides our existing backend, web UI and the Android Compose app was too much work for us, as a small team of 3 people working part-time on this project. So we ditched our half finished SwiftUI app even though we already spent a lot of time on it. The switch to Compose Multiplatform was easier than expected and crucial to get the iOS app released soon after Android.

Accomplishments that we’re proud of

The user response has been incredibly encouraging. Already during the beta phase, we received a lot of positive feedback from users. Many of our existing web users are actively switching to the mobile apps, which validates that our concept translates well to mobile. And new users already say that after trying several established competitor’s apps, they are happy to have found the Kittysplit app.

What makes us most proud is that users immediately understand how to use the app. The simplicity and intuitive design we worked so hard to achieve on the web has successfully carried over to mobile. Users can start splitting expenses within seconds of opening the app.

What we learned

The technical transition from Android Compose to Compose Multiplatform turned out to be surprisingly smooth. We learned a lot about both technologies throughout the process.

Perhaps the most interesting learning curve was diving into the iOS ecosystem for the first time. We spent considerable time learning Swift and SwiftUI, only to eventually abandon that code when we switched to Compose Multiplatform. While it felt like wasted effort initially, understanding iOS development principles helped us make better decisions for the multiplatform approach.

We also learned the intricacies of iOS app publishing which was a completely new world for us as primarily Android developers.

What’s next for Kittysplit

Our immediate focus is on App Store Optimization to grow our mobile user base.

We’re committed to continuing our user feedback driven development approach. Our feature roadmap includes several highly requested additions:

Expense attachments (receipts, photos)
Expense categories for better organization
Push notifications to keep everyone updated
And much more!

The goal remains the same: keep Kittysplit the easiest way to split group expenses, whether you’re using our web app or mobile apps.

Collecting Reviews in a Compose Multiplatform App

Fri, 26 Sep 2025 00:00:00 +0000

Shipping a great app is only half the battle, earning high quality reviews is just as crucial for App Store Optimization (ASO). Ratings and reviews shape first impressions, drive conversion, and influence store ranking. For a product like Kittysplit, where trust and simplicity are everything, timely and authentic user feedback helps future users decide to install, and helps us steer the roadmap.

But asking for reviews is a delicate craft. Prompt too early and you interrupt the flow, prompt too often and you annoy users, prompt at the wrong moment and you get low‑quality or frustrated feedback. In this post, we’ll share how we integrated Google Play’s ReviewManager and Apple’s SKStoreReviewController into our Compose Multiplatform app, and how we built a cross‑platform strategy to decide when to ask. We’ll cover the technical glue, the platform nuances, and the heuristics we use to surface the prompt at moments when users are most likely to feel satisfied, not interrupted.

Implementation

We’ll start with the implementation. We define a shared ReviewService API in common code and provide platform-specific implementations that wrap Android’s ReviewManager and iOS’s SKStoreReviewController. Using Kotlin Mutliplatform’s expect/actual mechanism in combination with Koin, we’re providing the correct implementation for each platform. This keeps the call site in our Compose Multiplatform UI identical across platforms, while letting each target handle its own prompt presentation in a native, compliant way.

We’re using a freshly created Compose Multiplatform project as the base for this post. You can find a little more detailed description of how to create a new CMP project in our previous blog post here. You can find all the code on GitHub.

At first, we need to add a few dependencies to our libs.versions.toml. If you don’t know what that is, you can read up on it here. It’s a relatively new way of managing dependencies in gradle.

[versions]
# ... other verions

android-play-review = "2.0.2"
koin = "4.1.1"
kotlinx-coroutines = "1.10.2"

[libraries]
# ... other libraries

android-play-review = { module = "com.google.android.play:review", version.ref = "android-play-review" }
android-play-review-ktx = { module = "com.google.android.play:review-ktx", version.ref = "android-play-review" }
koin-compose = { module = "io.insert-koin:koin-compose", version.ref = "koin" }
koin-core = { module = "io.insert-koin:koin-core", version.ref = "koin" }
kotlinx-coroutines-core = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "kotlinx-coroutines" }
kotlinx-coroutines-play-services = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-play-services", version.ref = "kotlinx-coroutines" }

./gradle/libs.versions.toml

Next, we’re going to declare these dependencies in our compose app’s build.gradle.kts:

kotlin {
    // ... other settings

    sourceSets {
        androidMain.dependencies {
            // ... other android dependencies

            implementation(libs.android.play.review)
            implementation(libs.android.play.review.ktx)
            implementation(libs.kotlinx.coroutines.play.services)
        }
        commonMain.dependencies {
            // ... other common dependencies

            implementation(libs.koin.core)
            implementation(libs.koin.compose)
            implementation(libs.kotlinx.coroutines.core)
        }
    }
}

./composeApp/build.gradle.kts

Now we need to define an interface in commonMain that we’ll implement later in androidMain and iosMain respectively:

interface ActivityContainer

data object EmptyActivityContainer : ActivityContainer

sealed class ReviewResult() {
    data object Requested : ReviewResult()
    data object Failed : ReviewResult()
    data class RequestError(val code: Int) : ReviewResult()
}

interface ReviewService {
    suspend fun requestInAppReview(
        activityContainer: ActivityContainer = EmptyActivityContainer
    ): ReviewResult
}

./composeApp/src/commonMain/kotlin/com/kittysplit/reviewservicecmp/ReviewService.kt

Because Apple’s SKStoreReviewController and Google Play’s ReviewManager don’t expose whether a dialog was actually shown or acted upon, our API only reports Requested or an error. This keeps our contract honest and portable across both stores’ opaque review flows. Don’t mind the ActivityContainer interface and EmptyActivityContainer object, we’re going to explain that soon.

Android

Let’s look at the implementation for Android:

import android.app.Activity
import android.content.Context
import com.google.android.play.core.review.ReviewException
import com.google.android.play.core.review.ReviewManagerFactory
import kotlinx.coroutines.tasks.await

data class AndroidContextHolder(val activity: Activity) : ActivityContainer

fun ActivityContainer.activity(): Activity? = (this as? AndroidContextHolder)?.activity

class AndroidReviewService(val context: Context) : ReviewService {
    private val reviewManager = ReviewManagerFactory.create(context)

    override suspend fun requestInAppReview(activityContainer: ActivityContainer): ReviewResult = try {
        val activity = activityContainer.activity()
        if (activity != null) {
            val reviewInfo = reviewManager.requestReviewFlow().await()
            reviewManager.launchReviewFlow(activity, reviewInfo).await()
            ReviewResult.Requested
        } else {
            ReviewResult.Failed
        }
    } catch (error: Exception) {
        if (error is ReviewException) {
            ReviewResult.RequestError(error.errorCode)
        } else {
            ReviewResult.Failed
        }
    }
}

./composeApp/src/androidMain/kotlin/com/kittysplit/reviewservicecmp/AndroidReviewService.kt

We implemented the Android side of ReviewService using Play Core’s in‑app review flow. AndroidReviewService creates a ReviewManager, requests a ReviewInfo using requestReviewFlow().await(), and then launches the prompt with reviewManager.launchReviewFlow(...).await(). Because launchReviewFlow requires an Activity, not a generic Context, we created a small container object to be able to hand over the Activity in the Android implementation. For iOS, we’re going to use the EmptyActivityContainer, since we don’t need to pass anything there.

If something goes wrong on Android, the ReviewManager might throw a ReviewException. In case we encounter it, we’re extracting the errorCode and return it as ReviewResult.RequestError. This allows you to handle these errors separately from the generic ReviewResult.Failed. For possible values of the errorCode see the documentation here.

iOS

Next, we’re going to implement the AppleReviewService in iosMain:

import platform.StoreKit.SKStoreReviewController
import platform.UIKit.UIApplication
import platform.UIKit.UISceneActivationStateForegroundActive
import platform.UIKit.UIWindowScene

class AppleReviewService : ReviewService {
    override suspend fun requestInAppReview(activityContainer: ActivityContainer): ReviewResult = try {
        val scene = UIApplication.sharedApplication.connectedScenes
            .filterIsInstance<UIWindowScene>()
            .firstOrNull { it.activationState == UISceneActivationStateForegroundActive }

        if (scene != null) {
            SKStoreReviewController.requestReviewInScene(scene)
        } else {
            SKStoreReviewController.requestReview()
        }
        ReviewResult.Requested
    } catch (_: Exception) {
        ReviewResult.Failed
    }
}

./composeApp/src/iosMain/kotlin/com/kittysplit/reviewservicecmp/AppleReviewService.kt

We implemented the iOS side with StoreKit’s in‑app review API. AppleReviewService looks up the currently active UIWindowScene by scanning UIApplication.sharedApplication.connectedScenes and picking the one in UISceneActivationStateForegroundActive state. If an active scene exists, we call SKStoreReviewController.requestReviewInScene(scene). Otherwise we fall back to SKStoreReviewController.requestReview(). Both calls are “fire‑and‑forget” (no success callback), so we return ReviewResult.Requested after invoking them. Any exception during lookup or invocation maps to ReviewResult.Failed. This approach ensures the prompt is tied to the foreground scene in multi‑window setups while remaining compatible with older, scene‑agnostic code paths.

Koin

That’s it. All we need to do now is wire it all together to be able to use it in our common app code. We’re going to use Koin for that, but you can go with any other DI framework.

import org.koin.core.module.Module

expect fun reviewModule(): Module

./composeApp/src/commonMain/kotlin/com/kittysplit/reviewservicecmp/ReviewModule.kt

import org.koin.core.module.Module
import org.koin.core.module.dsl.singleOf
import org.koin.dsl.module

actual fun reviewModule(): Module = module {
    singleOf(::AndroidReviewService)
}

./composeApp/src/androidMain/kotlin/com/kittysplit/reviewservicecmp/ReviewModule.android.kt

import org.koin.core.module.Module
import org.koin.core.module.dsl.singleOf
import org.koin.dsl.module

actual fun reviewModule(): Module = module {
    singleOf(::AppleReviewService)
}

./composeApp/src/iosMain/kotlin/com/kittysplit/reviewservicecmp/ReviewModule.ios.kt

We’re not going in detail here, but it should be straight forward. We’re defining a reviewModule() as an expect function and provide the platform-specific implementations in the actual counterparts.

With both implementations in place, you can inject ReviewService into any ViewModel and trigger review requests at the right moments in your user flows. Pick thoughtful triggers, wire them to requestInAppReview, and you’re ready to ask for reviews without disrupting your users.

Review triggers

We gate review prompts behind lightweight heuristics so they appear at moments of success, not interruption. We track when the app was first opened, total opens, when we last requested a review, and how many expenses a user has added. We use two trigger events: when a user adds an expense and when they settle up. We prioritized the settle-up event because it aligns with a clear success moment. Our heuristics are:

Last review request ≥ x days ago
First app open ≥ x days ago
App opened ≥ x times
Current Kitty has ≥ x expenses

We apply these on both platforms, but we’re more conservative on iOS, prompting less frequently and only after stronger engagement because the app is only three weeks old, and because Apple only displays the review prompt maximum 3 times a year.

Collecting reviews is both a technical integration and a product judgment call. With a shared ReviewService and platform-native implementations for Android’s ReviewManager and iOS’s SKStoreReviewController, you now have a clean way to prompt your users for reviews from your common code. Pair that with thoughtful heuristics that favor genuine success moments, and you’ll nudge happy users to share feedback without breaking their flow, ultimately improving ASO, conversion, and the product itself.

If you try this approach in your own Compose Multiplatform app, we’d love to hear what heuristics work best for you. Feels free to contact us on social networks (X, Bluesky, Instagram) or write an email.

Firebase Analytics in Compose Multiplatform without Cocoapods

Tue, 23 Sep 2025 00:00:00 +0000

At Kittysplit, we’ve always aimed to make splitting group expenses as effortless as possible. For years, Kittysplit was a web first product. As our users took Kittysplit on trips, into shared apartments, and to events, it became clear that we needed mobile apps on both Android and iOS.

In this post, we’ll provide a hands-on guide how we wired Firebase Analytics into our Compose Multiplatform app on both Android and iOS without using Cocoapods (which is going to retire soon).

From SwiftUI to Compose Multiplatform

We embraced Kotlin Multiplatform to share business logic across platforms, initially pairing it with a native Android app and a SwiftUI app for iOS, each with its own Firebase Analytics integration.

But when we decided to fully commit to Compose Multiplatform and retire our SwiftUI app, we hit a wall: there’s no out of the box way to use Firebase Analytics in a Compose Multiplatform project. Also, Cocoapods is going to retire soon. Instead, we’ll use the Swift Package Manager dependencies directly with the wonderful spm4Kmp plugin made by François. We’re also going to use Koin to wire it all together.

Project setup

We’re going to add Firebase Analytics to a newly created Compose Multiplatform project, which we’re creating using the new project wizard in Android Studio. If you want to follow along, you can either check out the project code from GitHub or create a new project yourself.

To create a new CMP project in Android Studio, make sure you have the Kotlin Multiplatform plugin installed. You can then click File -> New -> New Project.... Under “Phone and Tablet” select “Kotlin Multiplatform”, enter a name and package for your app and click “Next”. On the next screen, make sure you have the Android and iOS boxes ticked and select “Share UI” as UI implementation. Click “Finish” to create the new project.

Dependencies

Our first step is to add the needed dependencies. To do this, we’re going to use the gradle version catalog. Locate the libs.versions.toml file and add the following lines:

[versions]
# ... other dependencies

koin = "4.1.1"
spm4kmp = "1.0.0-Beta04"
firebase-analytics = "22.5.0"
google-services = "4.4.3"

# spm
spm-firebase = "12.0.0"

[libraries]
# ... other libraries

koin-compose = { module = "io.insert-koin:koin-compose", version.ref = "koin" }
koin-core = { module = "io.insert-koin:koin-core", version.ref = "koin" }
firebase-analytics-ktx = { module = "com.google.firebase:firebase-analytics-ktx", version.ref = "firebase-analytics" }

[plugins]
# ... other plugins

spm4kmp = { id = "io.github.frankois944.spmForKmp", version.ref = "spm4kmp"}
google-services = { id = "com.google.gms.google-services", version.ref = "google-services" }

./gradle/libs.versions.toml

You can now sync your project with the gradle files to pull in the dependencies. With this out of the way, we’re going to declare the dependencies in our build.gradle.kts files. We’ll start with the root build.gradle.kts file. Add this line:

plugins {
    // other plugins

    alias(libs.plugins.spm4kmp) apply false
    alias(libs.plugins.google.services) apply false
}

./build.gradle.kts

This just tells gradle to resolve the plugin, but not apply it. This is useful if you have a multi-module gradle project and only want to apply the plugin in a single submodule.

Now we’re going to set up the gradle.build.kts of our composeApp:

plugins {
    // other plugins

    alias(libs.plugins.spm4kmp)
    alias(libs.plugins.google.services)
}


kotlin {
    // ...

    listOf(
        iosArm64(),
        iosSimulatorArm64()
    ).forEach { iosTarget ->
        iosTarget.binaries.framework {
            baseName = "ComposeApp"
            binaryOption("bundleId", "com.kittysplit.firebase_analytics_cmp")
            isStatic = true
        }
        // This is the important part:
        iosTarget.compilations {
            val main by getting {
                cinterops.create("nativeIosShared")
            }
        }
    }

    sourceSets {
        named { it.lowercase().startsWith("ios") }.configureEach {
            languageSettings {
                optIn("kotlinx.cinterop.ExperimentalForeignApi")
            }
        }

        androidMain.dependencies {
            // ...
            implementation(libs.firebase.analytics.ktx)
        }

        commonMain.dependencies {
            // ...

            api(libs.koin.compose)
            api(libs.koin.core)
        }
    }

    swiftPackageConfig {
        create("nativeIosShared") {
            minIos = "16.0"
            dependency {
                remotePackageVersion(
                    url = uri("https://github.com/firebase/firebase-ios-sdk.git"),
                    products = {
                        add("FirebaseAnalytics", exportToKotlin = true)
                        add("FirebaseCore", exportToKotlin = true)
                    },
                    packageName = "firebase-ios-sdk",
                    version = libs.versions.spm.firebase.get(),
                )
            }
        }
    }
}

./composeApp/build.gradle.kts

That’s all dependency juggling. We added koin as “regular” multiplatform dependency of commonMain. For the Android implementation of Firebase Analytics, we added the Android library to androidMain. To be able to use the iOS Firebase Analytics in our iosMain implementation, we used spm4Kmp to declare the dependency. Notice the exportToKotlin = true, this tells spm4Kmp to export the dependency to kotlin, which means we can use it directly in iosMain code.

When you sync the project again, you’ll notice a new folder: ./composeApp/exportedNativeIosShared. This is the generated swift package which we’re going to add as a dependency to the iOS app next. Open XCode and navigate to the project dependencies:

XCode: iosApp -> PROJECT (iosApp) -> Package Dependencies

Click on the little “+” sign and then on “Add Local…”. Now select the aforementioned folder and click “Add package”. Once done, you’ll see all dependencies of Firebase Analytics and Firebase itself in your package dependencies on the lower left of your XCode window.

Firebase setup

To function properly, you need to register your Android and iOS Apps with Firebase. We’re not going to explain this in detail in this blogpost. Essentially, you need to provide a GoogleService-Info.plist file on iOS and a google-services.json file on Android. You can find an in depth guide for Android here. The guide for iOS is located here. Please note that you only need to follow the steps to obtain the aforementioned files, all other parts are covered in this blog post.

Implementation

This completes the boring part. We’re going to look at the implementation next. Our goal is to create a simple interface that allows us to track events to Firebase Analytics from view models, but also from Composables.

We’re starting by creating a simple interface inside commonMain, which we’re going to implement in androidMain and iosMain:

package com.kittysplit.firebase_analytics_cmp.analytics

interface Analytics {
    fun init()
    fun logEvent(name: String, params: Map<String, Any>?)
}

./composeApp/src/commonMain/kotlin/com/kittysplit/firebase_analytics_cmp/analytics/Analytics.kt

For the Android implementation, we’re going to use the kotlin Firebase SDK in androidMain:

package com.kittysplit.firebase_analytics_cmp.analytics

import androidx.core.os.bundleOf
import com.google.firebase.analytics.FirebaseAnalytics
import com.google.firebase.analytics.ktx.analytics
import com.google.firebase.ktx.Firebase

class AndroidAnalytics : Analytics {
    private lateinit var firebaseAnalytics: FirebaseAnalytics

    override fun init() {
        firebaseAnalytics = Firebase.analytics
    }

    override fun logEvent(
        name: String,
        params: Map<String, Any>?
    ) {
        val args = params
            ?.map { it.key to it.value }
            ?.toTypedArray()
            ?.let { bundleOf(*it) }

        firebaseAnalytics.logEvent(name, args)
    }
}

./composeApp/src/androidMain/kotlin/com/kittysplit/firebase_analytics_cmp/analytics/AndroidAnalytics.kt

As you can see, the implementation is straight forward. All we have to do is to convert our parameter map to a Bundle, which is often used in Android to pass data around.

On to the iOS implementation. We’re going to use the native iOS Firebase Analytics SDK in iosMain:

package com.kittysplit.firebase_analytics_cmp.analytics

import FirebaseAnalytics.FIRAnalytics
import FirebaseCore.FIRApp

class AppleAnalytics : Analytics {

    private val firAnalytics: FIRAnalytics.Companion = FIRAnalytics

    override fun init() {
        FIRApp.configure()
    }

    override fun logEvent(
        name: String,
        params: Map<String, String>?
    ) {
        firAnalytics.logEventWithName(name, params as Map<Any?, *>?)
    }
}

./composeApp/src/iosMain/kotlin/com/kittysplit/firebase_analytics_cmp/analytics/AppleAnalytics.kt

Dependency injection

All that is left to do now is to wire it all up using koin. We’ll have to create a module that provides our AppleAnalytics if we’re running on iOS and the AndroidAnalytics implementation if we’re running on Android. That’s where kotlin’s easy to use [expect/actual declarations] https://www.jetbrains.com/help/kotlin-multiplatform-dev/multiplatform-expect-actual.html come in.

In commonMain, we’re only declaring our module as an expect function, which is comparable to an interface where the implementation are provided per platform:

package com.kittysplit.firebase_analytics_cmp.analytics

import org.koin.core.module.Module

expect fun analyticsModule(): Module

./composeApp/src/commonMain/kotlin/com/kittysplit/firebase_analytics_cmp/analytics/AnalyticsModule.kt

Next, we’re providing the implementations for Android:

package com.kittysplit.firebase_analytics_cmp.analytics

import org.koin.core.module.Module
import org.koin.dsl.module

actual fun analyticsModule(): Module = module {
    single<Analytics> {
        val analytics = AndroidAnalytics()
        analytics.init()
        analytics
    }
}

./composeApp/src/androidMain/kotlin/com/kittysplit/firebase_analytics_cmp/analytics/AnalyticsModule.android.kt

And iOS:

package com.kittysplit.firebase_analytics_cmp.analytics

import org.koin.core.module.Module
import org.koin.dsl.module


actual fun analyticsModule(): Module = module {
    single<Analytics> {
        val analytics = AppleAnalytics()
        analytics.init()
        analytics
    }
}

./composeApp/src/iosMain/kotlin/com/kittysplit/firebase_analytics_cmp/analytics/AnalyticsModule.ios.kt

It’s important to call init on our implementations, to make sure they’re ready to go when they’re injected. Now we have to make sure that koin knows about the module we’ve just created. We’re going to do that by starting koin when our application starts. On Android, we can easily do that in the MainActivity:

package com.kittysplit.firebase_analytics_cmp

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.runtime.Composable
import androidx.compose.ui.tooling.preview.Preview
import com.kittysplit.firebase_analytics_cmp.analytics.analyticsModule
import org.koin.compose.KoinApplication

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        enableEdgeToEdge()
        super.onCreate(savedInstanceState)

        setContent {
            KoinApplication(application = {
                modules(analyticsModule())
            }) {
                App()
            }
        }
    }
}

./composeApp/src/androidMain/kotlin/com/kittysplit/firebase_analytics_cmp/MainActivity.kt

To make it work on iOS, we need to start the koin application in the MainViewController:

package com.kittysplit.firebase_analytics_cmp

import androidx.compose.ui.window.ComposeUIViewController
import com.kittysplit.firebase_analytics_cmp.analytics.analyticsModule
import org.koin.compose.KoinApplication

fun MainViewController() = ComposeUIViewController {
    KoinApplication(application = {
        modules(analyticsModule())
    }) { App() }
}

./composeApp/src/iosMain/kotlin/com/kittysplit/firebase_analytics_cmp/MainViewController.kt

Now we’re ready to inject our analytics implementation anywhere we need it. To test it, we’re going to use it to track the tap on the “Click me!” button from the example:

package com.kittysplit.firebase_analytics_cmp

// ... imports
import com.kittysplit.firebase_analytics_cmp.analytics.Analytics
import org.koin.compose.koinInject

@Composable
fun App(analytics: Analytics = koinInject()) {
    MaterialTheme {
        var showContent by remember { mutableStateOf(false) }
        Column(
            modifier = Modifier
                .background(MaterialTheme.colorScheme.primaryContainer)
                .safeContentPadding()
                .fillMaxSize(),
            horizontalAlignment = Alignment.CenterHorizontally,
        ) {
            Button(onClick = {
                analytics.logEvent("button_clicked", null)
                showContent = !showContent
            }) {
                Text("Click me!")
            }
            AnimatedVisibility(showContent) {
                val greeting = remember { Greeting().greet() }
                Column(
                    modifier = Modifier.fillMaxWidth(),
                    horizontalAlignment = Alignment.CenterHorizontally,
                ) {
                    Image(painterResource(Res.drawable.compose_multiplatform), null)
                    Text("Compose: $greeting")
                }
            }
        }
    }
}

./composeApp/src/commonMain/kotlin/com/kittysplit/firebase_analytics_cmp/App.kt

That’s it! You’re now ready to track events from anywhere in your Android Compose app. There’s one little thing we need to fix. You might have noticed that your preview is not showing any longer. That’s because koin is not initialized. Luckily, there’s a fix for that: we’re going to provide a fake instance of our Analytics for previews:

package com.kittysplit.firebase_analytics_cmp.analytics

import org.koin.dsl.module

fun noopAnalyticsModule() = module {
    single<Analytics> {
        object : Analytics {
            override fun init() {}

            override fun logEvent(name: String, params: Map<String, String>?) {}
        }
    }
}

./composeApp/src/commonMain/kotlin/com/kittysplit/firebase_analytics_cmp/analytics/NoopAnalyticsModule.kt

Now all we have to do is wrap our previews with a little helper:

@Preview
@Composable
fun AppPreview() {
    KoinApplicationPreview(application = { modules(noopAnalyticsModule()) }) {
        App()
    }
}

Now you should see the preview again.

We hope this little guide helps you in your multiplatform endeavours. We had a lot of fun implementing the Kittysplit apps in Compose Multiplatform.

Building Kittysplit's Mobile Apps in Compose Multiplatform

Thu, 18 Sep 2025 00:00:00 +0000

After 13 years as a web only application, Kittysplit has finally made the leap to mobile. We initially planned to build separate Android and iOS apps using Kotlin Multiplatform for shared business logic, but Compose Multiplatform’s recent stability changed everything. Here’s how we went from web only to native mobile apps.

From Web only to Mobile: A 13 Year Journey

Kittysplit started as a web application back in 2012. For over a decade, we maintained it exclusively as a webapp. The web platform allowed us to provide universal accessibility. Anyone could create or join a Kitty simply by opening a link in their browser, regardless of their device type. This cross platform compatibility is crucial for group expense sharing, where participants often use different devices and operating systems.

Growing Demand for Native Apps

However, user requests for dedicated mobile apps grew year after year. We felt that we needed to address this demand, so we looked at the available options for the implementation. We evaluated React Native, Flutter, Kotlin Multiplatform, and Compose Multiplatform to determine the best approach for our small development team.

Because we already had experience with Android development, we chose Kotlin Multiplatform as our foundation. Our initial plan was straightforward: develop the Android app first using Android Compose, while implementing all business logic in a shared module in Kotlin Multiplatform. This would allow us to share the core functionality across platforms: networking, business logic, calculations and local storage. We planned to build the iOS app using SwiftUI after completing the Android app, leveraging the already written shared business logic.

The Power of Kotlin Multiplatform

Kotlin Multiplatform proved to be an excellent choice for our architecture. We implemented all networking, local storage, and client-side calculations in the shared multiplatform code. Additionally, we moved all our ViewModels into the shared codebase, ensuring consistent business logic and state management across both platforms.

The implementation was straightforward: Kotlin provided almost everything we needed out of the box. For local data storage, we used SQLDelight, which allowed us to write type-safe SQL queries. We integrated the RevenueCat Purchases multiplatform SDK for handling Super Kitty upgrades. To enhance the Swift interoperability for our planned iOS development, we used SKIE from TouchLab. For dependency injection, we chose Koin, which worked seamlessly across our multiplatform setup. This foundation gave us confidence that we could maintain a single source of truth for our core functionality while building native experiences on each platform.

Compose Multiplatform Goes Stable

As it’s often the case in software development, the SwiftUI frontend turned out to be more work than we initially anticipated 🙈. We had been following Compose Multiplatform’s development for some time. Given the challenges we were facing with SwiftUI, we decided to experiment with it for a few days. Compose Multiplatform for iOS had recently reached stable status in May 2025.

We managed to migrate our app to Compose Multiplatform within just a few days, which was much faster than we expected. The resulting app ran smoothly on our iOS devices and felt really well.

This led us to ditch the native SwiftUI frontend entirely and go with Compose Multiplatform instead. It would save us months of work, both now and in the future. With only one codebase to maintain, we can spend our time improving the app and adding new features rather than implementing everything twice.

Kittysplit on iOS

The Migration Process: From Android Compose to Compose Multiplatform

The actual migration process was surprisingly straightforward. We started by importing the new Compose Multiplatform dependencies and migrating to multiplatform resources, which was mostly just copying a few files to the new structure. The main code changes involved removing usages of the Android Context throughout our codebase.

Fortunately, we had already been using multiplatform libraries from Sentry and RevenueCat, so those integrations continued to work without any changes. For Firebase Analytics, we used the expect/actual mechanism to provide platform-specific implementations. We also needed to make our deep links work on both platforms, but the patterns were similar enough that it didn’t require major restructuring.

Most of our existing Compose UI code worked with minimal adjustments, and the shared ViewModels we had already implemented in Kotlin Multiplatform integrated seamlessly. Within just a few days, we had a fully functional iOS app that felt genuinely good.

Looking Forward

We’re excited about the future of Kittysplit’s mobile apps with this technology stack. Kotlin Multiplatform and Compose Multiplatform have given us the perfect balance of development efficiency and native performance. With a single codebase to maintain, we can focus on what matters most: building features that make splitting expenses even easier for our users. We’re already working on several improvements and new features that would have taken us much longer to implement across separate platforms. The mobile app journey has finally found its ideal technical foundation, and we couldn’t be more excited about where it’s headed.

O Kittysplit chegou ao celular: conheça nossos apps para Android e iOS

Wed, 10 Sep 2025 00:00:00 +0000

Depois de mais de uma década só na web, o Kittysplit finalmente tem apps nativos para Android e iOS! Desde o lançamento em 2012, a gente ajuda amigos, gente que divide apartamento e grupos de viagem a dividir despesas de um jeito justo e sem dor de cabeça com o nosso app web.

Por que apps para celular? Por que agora?

A gente sempre quis criar a forma mais acessível possível de dividir despesas. Durante anos, nosso app web deu conta do recado: qualquer pessoa com um navegador conseguia organizar as despesas do grupo sem complicação. Mas ouvimos o seu feedback e percebemos que muitos de vocês preferem a praticidade de um app próprio no celular.

Acesso imediato: às despesas do grupo sem precisar abrir o navegador
Uso mais fluido: feito especialmente para celular

O mesmo Kittysplit de sempre

Por mais animados que a gente esteja com os apps, pode ficar tranquilo: o Kittysplit continua o mesmo. Seguimos firmes em:

Simplicidade: nada de recursos complicados que você não precisa.
Sem cadastro obrigatório: crie Kitties sem criar uma conta.
Divisão justa: várias opções para dividir as despesas de forma equilibrada.
Uso básico grátis: as funções principais continuam gratuitas.
App não obrigatório: os apps são para quem quer uma experiência mais fluida no celular, mas o Kittysplit na web continua existindo.

Nosso compromisso com a web

A gente acredita em dar opções. Por mais felizes que estejamos de finalmente ter apps, queremos deixar claro que continuamos totalmente comprometidos com a versão web. Sabemos que nem todo mundo quer baixar mais um app, e a flexibilidade da web continua valendo muito para bastante gente.

A versão web do Kittysplit vai continuar recebendo a mesma atenção, as mesmas atualizações e os mesmos recursos novos que os apps.

Baixe hoje mesmo!

Os novos apps já estão disponíveis na App Store da Apple e na Google Play Store. Seja você alguém que usa o Kittysplit há anos ou que acabou de conhecer, convidamos você a experimentar os apps, sem abrir mão da flexibilidade da versão web.

Ou continue usando nosso app web em kittysplit.com

O que vem por aí?

O lançamento dos apps é só o começo. Já estamos trabalhando em melhorias e novos recursos com base em todo o feedback de vocês.

Adoraríamos saber o que você achou dos novos apps e ouvir suas sugestões para as próximas melhorias! Como sempre, nosso objetivo é deixar a divisão de despesas o mais simples e tranquila possível, agora em ainda mais plataformas.

O Adsense está quebrado

Thu, 28 Mar 2024 00:00:00 +0000

Já tivemos problemas com anúncios golpistas no Adsense há vários anos. Golpes bem óbvios, como o falso alerta de vírus de 2018, parecem ter sumido, mas outros anúncios golpistas apareceram.

No ano passado, um usuário entrou em contato pedindo para cancelar a assinatura dele, só que o Kittysplit não oferece nenhuma assinatura. Logo descobrimos que ele tinha caído num golpe de um anúncio fraudulento exibido enquanto usava o Kittysplit no celular.

Como o usuário foi enganado

O golpe é simples: o anúncio mostra um enorme botão verde COMEÇAR, fingindo fazer parte do Kittysplit. Mas o botão leva o usuário a um site de terceiros que pede os dados do cartão de crédito. O site finge que a cobrança é por um serviço do Kittysplit (por exemplo, acertar as contas com os amigos, ou uma taxa para usar o site). No começo é grátis ou quase grátis, mas depois passa a cobrar uma assinatura mensal de 20 a 60 €/$/£ por um serviço que o usuário nunca quis.

Aqui vai uma captura de tela de um anúncio enganoso:

Assim que ficamos sabendo do problema, agimos rápido e começamos a bloquear esses anúncios na Central de revisão de anúncios do Adsense. Por um tempo isso pareceu resolver, mas os anúncios continuaram voltando em versões diferentes, sempre com um botão grande e chamativo dizendo COMEÇAR, CONTINUAR, PRÓXIMO, BAIXAR ou algo parecido.

Alguns meses atrás, outro usuário que também tinha caído no golpe desses anúncios entrou em contato. Então bloqueamos os anúncios enganosos de novo e de novo, passando muitas horas bloqueando milhares de anúncios e centenas de contas de anunciantes, na esperança de que isso resolvesse o problema. Mas não parava, e não importava quantas vezes bloqueássemos esses anúncios, eles voltavam depois de alguns dias.

Por que decidimos parar de exibir anúncios para proteger nossos usuários

Acontece que é impossível pegar todos os anúncios maliciosos, e há pouco tempo um terceiro usuário caiu no golpe. Então decidimos que já era demais e desligamos todos os anúncios no mês passado. Isso quer dizer que o Kittysplit agora está livre de anúncios (uhul!) até encontrarmos outra solução de publicidade ou até o Adsense resolver o problema. Sabemos que ninguém gosta de anúncios mesmo, mas dependemos da receita com publicidade para que as Kitties gratuitas continuem gratuitas para você.

Mesmo que isso nos custe dinheiro em receita perdida, para nós é mais importante proteger nossos usuários de golpes de anunciantes mal-intencionados.

Mas por que isso ainda acontece?

A verdadeira pergunta é por que o Adsense ainda deixa esses anúncios voltarem. Eles claramente violam as políticas do Adsense (Declarações falsas: design de anúncio enganoso): anúncios que dificultam para o usuário perceber que está interagindo com um anúncio não são permitidos.

Então por que o Adsense continua exibindo esses anúncios? Deveria ser bem simples detectá-los e bloqueá-los. Qual é, estamos em 2024, vocês são o Google e têm IA e tudo mais. Cada dono de site passar horas e horas bloqueando cada anúncio, um por um, toda vez que ele volta depois de um ou dois dias, claramente não é uma solução viável. O Google/Adsense tem que resolver isso do lado deles!

O Google afirma que usa aprendizado de máquina e IA para bloquear anúncios. Mas até a IA mais rudimentar de 2024 deveria conseguir detectar com facilidade um botão verde enorme dizendo “CONTINUAR”. Mesmo assim, os anúncios continuam voltando.

Qual é o problema, Adsense?