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.
GIMP - GIMP is a multiplatform photo manipulation tool.
MediBang Paint - The official site for MediBang Paint, the free digital painting and manga creation software. You can download the latest version of MediBang Paint here, and get news and tutorials.
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Corel Painter - Corel Painter is media painting software.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.