Pixlr - Pixlr® makes it easy to transform everyday images into stunning works of art.
GIMP - GIMP is a multiplatform photo manipulation tool.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
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.
Adobe Photoshop Express - Easily edit and share your photos in no time!
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.