Being realistic, no. I think if someone wants to learn to draw they'd be better off starting with pencil and paper. I doubt you could write an app that could teach anything meaninful. If it's giving you outlines to colour in and stuff, you aren't really learning to draw. You'd be better off just putting some time in practising freestyle. I guess you could start off trying to copy some paintings or something. But even though it's possible to get some pretty good results in mypaint on the n900 I don't think I'd recommend it as a starting point for beginners! Who knows though, maybe I'm just old fashioned and only think pencil and paper's the best starting point because that's the way I did it.