Clip Studio Paint - The artist's software for drawing and painting.
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.
Autodesk SketchBook - SketchBook drawing and painting software provides designers, architects, and concept artists the tools to sketch ideas quickly and create beautiful illustrations.
ibis Paint X - Drawn with + ibisPaint
FireAlpaca - FireAlpaca is the image editor that can be used readily and easily.
Artrage - A simple but lovely natural media painting and sketching program.