Undo as an Inverse-Clock

Paper, which is a free sketching app on the iPad, has a lovely implementation of the undo. It was kind of tricky to bring up the undo, but when I figured how, it was just beautiful. When the widget comes up you can go back in time by moving the finger with a rotatory motion. It animates the progressive undo of every stroke. It is like an inverse clock. Brilliant!

Posted in: history, iPad, widget