Gimp is an open source, professional photo and image editor similar to Adobe Photoshop. It is 100% free and can be downloaded here:
https://www.gimp.org/downloads/
Check out these other videos for step by step instructions on how to Download and Install:
Install on Windows:
https://www.youtube.com/watch?v=cqaDOyNQy4o
Install on Linux:
https://www.youtube.com/watch?v=hINOseZJeyI
Find more great free software at http://tjfree.com/
