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.
Excalidraw - Excalidraw is a whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.
Autodesk SketchBook - SketchBook drawing and painting software provides designers, architects, and concept artists the tools to sketch ideas quickly and create beautiful illustrations.
Sketch Toy - A drawing application that lets you save and share replays of your work with friends.
Clip Studio Paint - The artist's software for drawing and painting.
Sketcharama - Draw a given word and let the other players guess your sketch.