GIMP

If you like professional image editing or if you're a fan of Photoshop, this software's for you! 

GIMP is a free and open-source raster graphics editor used for image retouching and editing, free-form drawing, converting between different image formats, and more specialized tasks. GIMP is released under GPLv3+ licenses and is available for Linux, macOS, and Microsoft Windows.

Overview and Features

GIMP:

• Is free!!!
• Has almost all the tools of Photoshop
• Is portable, meaning, it does not take much of your hard disk space
• Is perfect for those who wants to buy Photoshop but doesn't have much money

Screenshots

Download

Given below is a copy-paste from the official GIMP website download page.

GIMP for Windows*

Download GIMP 2.10.8
via BitTorrent Download GIMP 2.10.8
directly

*GIMP is also available for Linux, OS X and macOS. You can get them by visiting the official GIMP website download page.