Sketchable - Creators of Sketchable!
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Corel Painter - Corel Painter is media painting software.
ZEN - Put your finances in order with ZEN – integrated tool which will introduce stability to your budget.
GIMP - GIMP is a multiplatform photo manipulation tool.