Watch a big rectangle, which is subdivided and filled with smaller ones, resulting in a colorful pattern. You can change the speed, the final expected rectangle sizes and color schemes of the parts. The settings of app and wallpaper are shared, and can be easily adjusted and tested.
Upon completion of the wallpaper pattern, you can tap it to start with a fresh rectangle. In the app just turn your phone or restart through the options menu.
Not useful for anything, but relaxing and fun to watch.