Artist's Touch

For $4.99, Artist's Touch turns your finger into a pastel crayon, pencil, charcoal, or eight other mediums for changing a simple snapshot on your iPhone into a work of art. Or an approximation thereof at least.

What's key is that the app starts by doing a blueprint mapping of any photo you use. You then select your medium and one of six surfaces if you want and start stroking the screen. Finer brushes bring out finer detail so you can make things as abstract or realistic as you want.