Nimbus is a reference application, a compendium of several techniques and architectural implementations on a test use-case on the Android platform.
The main purpose for this app is to try and find common ground to step upon the chasm between iOS and Android native development. The iOS equivalent project is Nimbus for iOS.
For that reason, several programming concepts and methodology that are commonly practiced in Android might appear differently in this project since they might originate from the iOS world (and vice versa) or are altered to serve the platform convergence.