Android part of the PebbleDialer app.
See http://forums.getpebble.com/discussion/5767/android-pebbledialer-new-call-controls-for-your-pebble
To build this project properly, you will also need PebbleAndroidCommons directory next to PebbleDialer one. Latest release at this moment (2.42) requires version r1. Then you just open PebbleDialer directory with Android Studio and it should automatically resolve all dependencies.