This is a great animation app that works very nicely without any lag. The tools are simple and the UI is clean. It provides the fundamental tools needed to do 2D animation without any fancy ones that would clutter up the small screen on a smart phone. I highly recommend this app for any animator that wants a way to animate on-the-fly as one might sketch in a portable sketchbook. It has one irritating feature in that it nags you to write a review every time you open the app even when you already have written a review.