There are plenty of completely free alternatives to Photoshop ; here do in the desktop version (there are only three brush sizes to choose from, for instance). It's not quite as feature-rich as Adobe's powerhouse, but it comes.
Adobe Photoshop products organize, edit, and create images.
Download free trials and updates for all products including Creative Cloud, Photoshop, InDesign, Illustrator, Acrobat Pro DC and many more. How To Download Adobe Photoshop CS6 For Free (Full Version)