Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
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.
TwistedBrush Pro Studio - A powerful and unique natural media painting program.
GIMP - GIMP is a multiplatform photo manipulation tool.
Corel Painter - Corel Painter is media painting software.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.