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
Clip Studio Paint - The artist's software for drawing and painting.
Pixelitor - Pixelitor is a cross-platform raster graphics editor written in Java.
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.
RealWorld Photos - RealWorld Photos is an free portable photo editor for Windows.