Just in case anyone hasn't seen it, I can highly recommend the "Cavern" roguelike on iOS, for anyone looking for portable roguelikes
http://www.cavern2.com/Since I discovered it I've been playing it at every opportunity in work, and quite a lot at home too, it's that good (in my opinion). I think the biggest draw for me is having a town that you can teleport back to where you can sell your unwanted stuff and upgrade your gear, along with the Diablo-esque generated items that you come across.
I emailed the author with some feature requests for the next version (there is another version on the way), so hopefully some of those might be incorporated. Unforunately the next version will rqeuire iOS 7, which is too new for my iPod Touch 4, but I'm seriously considering upgrading to iPod Touch 5 just so I can play the next version, which seems will be even better.
I also asked the author if an Android version was in the works (I have a much newer Android device), but it seems like that is on hold, for now at least, but that it could be possible in the future.
But yes, an excellent portable Roguelike in my opinion, certainly the best one I've come across so far.