I just open sourced my first Android app, reddit is fun. I did it because I won't have time to maintain it anymore (or if I do have time, I think I'm ready to move onto other projects). Hopefully people will find it useful, or even better, contribute to it. Contributions could be in the form of better themes, improved layouts, and added features (like offline caching).
I chose GPL over the Apache license because I think GPL makes more sense here. I gave it a lot of thought, and I think that if I use GPL (which requires derived works to also release their source under GPL) then it'll be easier for people to contribute to a "community" sort of app. The alternative under Apache would be that people could take the code and do whatever they wanted, and then keep the changes to themselves as closed source. Which might be good if people want to make a really high quality reddit app and keep the source to themselves. But really, I can't see additions to the current code being so drastic that people would want to hide their changes.
Git repository: http://github.com/talklittle/reddit-is-fun/tree