I have implemented an Android application called Liigavahti. It is only in Finnish, but basic idea is to provide Finnish ice hockey news streams to users. Application includes Twitter stream as well.
When implementing the application I found out couple of great libraries that helped me a lot and I would like to share them to you:
ActionBarSherlock is an extension of the support library designed to facilitate the use of the action bar design pattern across all versions of Android with a single API.
Basically it provides same functionality than native ActionBar to older Android versions.
ViewPageIndicator provides paging indicator widgets compatible with the
ViewPager from the Android Support Library and ActionBarSherlock. Also here this library brings functinality of ViewPager to older Android versions
Android-PullToRefrehs project aims to provide a reusable Pull to Refresh widget for Android. You have seen this kind of functionality in several mobile apps like Twitter and Facebook. This library makes it easy to implement that kind of functionality.
GitHub Android App [https://github.com/github/android]
Actually this is not a library, but why I mention this is the reason that it helped me a lot to understand how to do things right way. So if you have some spare time I suggest you to check this out. Be careful you might learn something
When I was implementing my application I struggled a while with examples I found. So I will provide some simple tutorials how to use these libraries. So stay tuned!