RealWorld Photos - RealWorld Photos is an free portable photo editor for Windows.
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.
Online Image Editor - Online editor for images and animated gifs with multiple effects and tools
Autodesk SketchBook - SketchBook drawing and painting software provides designers, architects, and concept artists the tools to sketch ideas quickly and create beautiful illustrations.
SoftColor PhotoEQ - SoftColor PhotoEQ makes color correction, image editing and color management tasks simpler.
Clip Studio Paint - The artist's software for drawing and painting.