1. Timber – A simple utility to make logging bit more easier for your Android applications.
2. Roboguice – The Android Injection framework. After using it for a while, I really feel that It is a must for any android project. But on the downside, this library is poorly documented. Expecting a good documentation along with 3.0 release. If you want to use this library then look at the existing projects with roboguice at github to get an idea.
3. Retrofit –