Mobius is a functional reactive framework for managing state evolution and side-effects, with add-ons for connecting to Android UIs and RxJava Observables. It emphasizes separation of concerns, testability, and isolating stateful parts of the code. To learn more, see the wiki for a user guide. To see Mobius in action, check out the sample TODO app based on the app from Android Architecture Blueprints. You can also watch a talk from Android @Scale introducing Mobius.