Muh Triangles brings Colorful and Animated Triangles on your Home Screen, with lots of customization.
Colors can change with the time of day, the day of year, the remaining battery percentage, and more.
Several gradient types are supported.
It is very light on the battery and doesn't hog system resources.
-Phone State: to read battery percentage
-Internet: for ads (only shown in the settings page)
Source code: https://github.com/adolfintel/muhtriangles-android