I recently published my first app for the Android platform. My main goal was to get my feet wet with Android development, and the Assistant Coach app seemed like a fairly simple idea that, as far as I could tell, hadn’t been done before.
The whole process took me about a month, working part-time. I really enjoyed the process; the Android documentation is excellent, and the architecture is designed well. It had been a while since I did any Java development, but I fell back into it pretty easily (esp. thanks to Eclipse). I had a blast and am thinking about what to make next. Let me know if you have any ideas!