FireAlpaca

FireAlpaca is a very simple image editing tool with which you can modify your photographs using a more user-friendly interface than that of the majority of competitors such as GIMP or Photoshop.

The amount of tools you will have, consequently, is certainly limited. However, it offers enough features for you to be able to retouch your images without a problem, using things such as layers, magic wand, and gradient brushes.

Additionally, the program comes with tons of keyboard shortcuts (some of which are known by Photoshop users) so you can easily move around the program interface. Having a limited amount of options plays in your favor when learning all the important shortcuts.

FireAlpaca is a good image editor alternative. Beyond being very light and completely free, it offers enough quality to straighten out practically any photo.