Contributors are more than welcome. Just upload a PR with a description of your changes. Lottie uses Facebook screenshot tests for Android to identify pixel level changes/breakages. Please run ./gradlew --daemon recordMode screenshotTests before uploading a PR to ensure that nothing has broken. Use a Nexus 5 emulator running Lollipop for this. Changed screenshots will show up in your git diff if you have.

If you would like to add more JSON files and screenshot tests, feel free to do so and add the test to LottieTest.