Random lines and other random drawings.
For the casual user: to show off how fast your phone or tablet can be, if it is really pushed to its limits. Do not forget to uninstall it after five minutes. It uses up 0.02% of memory of your phone, and it is unlikely that you will need it again. And if you do, you can always donwload it from the store in minutes.
For programmers: It is good template for creating more serious programs, where one thread calculates complex images and another thread displays them.
The application is ad free, and open-source (link is at the bottom of the store page). Licensed under GNU GPL V2.0.