Developer Drippler has turned its Step Counting live wallpaper into an open source Android Experiment. The wallpaper uses your Google Fit data to visualize the steps you've taken, filling up a water drop as you take more. Now, other developers can take a look at Drippler's code to help them build similar projects.
In addition to tracking your steps, the live wallpaper also responds to motion, with the "water" in the drop moving based on the angle of your phone. Drippler gave some insight into how they built the app on its Android Experiments page:
A Live Wallpaper that utilizes the Android Fit API - your steps are visualized by filling up water in the water drop, when the drop is full of water that symbolizes that the user has reached their step goal.
Head over to the Android Experiements site at the link below to take a look at the code for yourself. You can also get Drippler Fitness: Step Counter itself on the Google Play Store.
Source: Android Experiements