The Psykopaint web version (try it!) is something I played with when I first started experimenting with digital art. I always hoped they would develop an app and after two years in the making it's ready to release.
Here's some info about Psykopaint that Mad Captain Mathieu (developer) allowed me to post here:
1. It’s the first painting software to be full 3d. So you can stack multiple layers of paint on top of each others, and paint on different surfaces (Canvas, Paper, Wood) using different materials that have different glossiness. When you move your iPad around it will reflect the light changes on your painting. It feels like holding the real thing. Making it the most realistic painting application ever built since cave painting.
No one in their right mind would get into such details and spend 2 years on it!
2. The brushes have been given extreme attention: some react to gravity, some react to the texture you draw upon (Pencils), some not just look but behave like the real thing (Watercolors), some allow you to be lazy (Paint Guns), and some to be like Van Gogh 2.0 (Paint Brushes)
3. You can paint from a photo like the current web version, and for the first time you can paint using the color tones of famous paintings like Da Vinci’s Mona Lisa or Van Gogh’s Starry Night. So if you take a crappy photo with your iPad it will still look like you know what you’re doing.
I wouldn’t dare to put in buzzwords like it’s “revolutionary” cause it’s lame and it would sound like an Apple ad. So I’ll just tell you it’s a really awesome piece of painting software that you ought to try. Especially since...it’s FREE with the first brush styles are included. (Spray Cans) And you’d pay if you want the other brushes: Watercolors, Pencils, Paint Guns, and Paint brushes.
Watch Psykopaint for iPad in action here