Alexandre Gherschon has created a portal for finding out useful Android libraries, github resources. I am sure it would help Android developers a lot.
Check: The Ultimate Android Library
You can even download and check Android app too: The Ultimate Android Library
The Ultimate Android Library (T.U.A.L.) is an app for developers. The aim of the app is to bring the latest and best android resources (libraries, icons, etc.) to developers for them to enhance their current and future apps. From the website (http://www.theultimateandroidlibrary.com) you can send a resource you’re interested in to see it in your phone and download the demo app if there’s one, etc.