Meritous is a nice, addictive action-adventure dungeon crawl game. Each new game is unique since the dungeon is built in a semi-random fashion. Last but not least, the engine, graphics and sound effects are GPL'd
The game is based on SDL 1.2, which has an unofficial Android variant, so I decided to try and port it on my cell phone! The port was surprinsingly smooth and only non-SDL fixes (move big stack allocation to heap) were necessary. Who said it was difficult to program in C on Android?
It was also an opportunity to study the build system for F-Droid, an app market for free software apps, where APKs are rebuilt from source. The spec-like file is here.
You can download the very first (aka beta) Android version: