Open Peeps - A hand-drawn illustration library.
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.
skribbl - Word guessing based on drawing.
Artrage - A simple but lovely natural media painting and sketching program.
Fontself Maker for Photoshop - Turn any lettering into color & vector fonts
Procreate - Procreate is the most powerful and intuitive digital illustration App available for iPad®.