GIMP 

org.gimp.gimp-3.0

GIMP (org.gimp.gimp-3.0) is a Mac OS X software application that has been discovered and submitted by users of iBoostUp.

Description:
GIMP, the GNU Image Manipulation Program, is a powerful, open-source alternative to Adobe Photoshop that offers a robust set of tools for image editing and creation. While its interface may not be as polished as some commercial options, GIMP's extensive feature set and active community make it a solid choice for both amateur and professional users looking for a free image editor.