I'm experimenting with the ArtRage app on the iPad. The coati sketch is based on modifying a draw-a-raccoon pose, although since coatis aren't as pudgy as raccoons as a general thing I had to improvise. The big advantage ArtRage seems to offer is that its line is less jittery for me and coloring seems to be smoother. Apparently it's meant to more closely approximate the way real paint on real paper works. I haven't done anything with real paint and real paper in real long so I don't know how true that is.