According to Wikipedia: Doodle is unfocused drawing made while a person's attention is otherwise occupied. Doodles are simple drawings that can have concrete representational meaning or may just be abstract shapes.
People like doodle game, like drawing on the napkin, design draft UI, sketch, etc. You can even change the brightness using swipe up and down.
Design for iphone and ipad.
Support for iphone 5.
This time is "Doodle Clock", clock for people who love doodle.