This week's book giveaway is in the Other Languages forum. We're giving away four copies of Functional Reactive Programming and have Stephen Blackheath and Anthony Jones on-line! See this thread for details.
I have done some unit testing of Android apps. I have very carefully layered my app so that the business logic is in POJOs with no dependency on the Android SDK; I test those with standard JUnit test cases. I have also used the Android SDK unit test framework to check the app's UI, but that is often trickier.