ArtRage the iPad, another must have painting tool for the iPad. I love the oils and watercolor, the look and feel is the most realistic of the iPad apps. The interface is nice and simple. Big watercolor brushes tends to bog down a lag a bit, but well worth it for the natural look.
This is a painting that I painted tonight with pencil and watercolor on ArtRage. Doing this made me realize how much I miss doing traditional watercolor.... Maybe it's time to break out the old paints :)
ArtRage for the iPad: http://www.artrage.com/artrage-ipad-main.html