This isnt as good as I had hoped it would be. It has the advantage of adding photos so you can trace them and it allows you to adjust pen sizes, but thats about it. The pen control is flimsy at best, and it doesnt give you many options for drawing tools. There are other apps that do a lot better job and are worth your money.
Pilot/CFI - Denton about SketchTime - Quick Sketching & Photo Tracing