Pinch to zoom works well, and there's a proper undo button, that rolls back a limited number of times.
There are layers, but I couldn't suss out how they worked, it could be they are unlocked in the pro version, which is advertised every now and then in a pop up.
Export goes to photo album, and that's it.
I enjoyed using it.
Today's challenge was to draw awesome... not much more awesome than Godzilla.