This sample app is available at, which can be checked out and run once Skip is installed.


This is a Skip dual-platform app project. It builds a native app for both iOS and Android that renders an embedded Lottie JSON animation using the SkipMotion framework.


This project is both a stand-alone Swift Package Manager module, as well as an Xcode project that builds and transpiles the project into a Kotlin Gradle project for Android using the Skip plugin.

Building the module requires that Skip be installed using Homebrew with brew install skiptools/skip/skip.

This will also install the necessary transpiler prerequisites: Kotlin, Gradle, and the Android build tools.

Installation prerequisites can be confirmed by running skip checkup.


The module can be tested using the standard swift test command or by running the test target for the macOS destination in Xcode, which will run the Swift tests as well as the transpiled Kotlin JUnit tests in the Robolectric Android simulation environment.

Parity testing can be performed with skip test, which will output a table of the test results for both platforms.


Xcode and Android Studio must be downloaded and installed in order to run the app in the iOS simulator / Android emulator. An Android emulator must already be running, which can be launched from Android Studio’s Device Manager.

To run both the Swift and Kotlin apps simultaneously, launch the LottieDemoApp target from Xcode. A build phases runs the “Launch Android APK” script that will deploy the transpiled app a running Android emulator or connected device. Logging output for the iOS app can be viewed in the Xcode console, and in Android Studio’s logcat tab for the transpiled Kotlin app.

Project Structure

This project was initialized with the command:

skip init --show-tree --icon-color='1abc9c' --appid=skip.lottie.demo.App --version 0.0.1 skipapp-lottiedemo LottieDemo:skip-motion/SkipMotion:skip-ui/SkipUI