"Koi Live Wallpaper is easily one of the most eyecandy Android
application. Koi Live Wallpaper features colorful fishes and
interactive water. Everything is 3D rendered in OpenGL 2.0, with
fully interactive water that supports multitouch. And don't worry,
Koi Live Wallpaper is not much of a resource hog, won't drain your
battery. To unlock full set of features, you have to upgrade to the
paid version of Koi Live Wallpaper."