To get back into android development I've decided to port the somewhat mesmerising Dali Clock to android. The original was coded by Jamie Zawinsky (jwz).

It is implemented both as a daydream and a normal app. It's not (yet?) available on the play store, but you can download the source and apk here: http://www.jwz.org/xdaliclock

More info and Jamie's announcement: http://www.jwz.org/blog/2015/04/dali-clock-2-42-android