VistaCreate - The VistaCreate is a free and global digital platform which is known for sharing, searching, finding, and creating great art.
GIMP - GIMP is a multiplatform photo manipulation tool.
PaintCAD - Pixel art image editor, created for full keyboard control of image drawing without mouse using.
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.
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.