Boomerang is the game I keep trying to build on whatever new framework/engine/language I'm learning. This here is Java/libGDX iteration.
Frankly, I don't remember. The project should be opened in Android Studio and I think Gradle should do the rest. I only tested it on Android.
Just tap the lower part of the screen to launch the bottom boomerang and the higher part to launch the top boomerang. The AI is also implemented and should help you launch the top one.