Since gimp is considered somehow a heavy-weight program, at least for basic image editing, I searched in Ubuntu repositories for a quicker alternative and I found “Mirage”, it’s very simple and contains nice features such as:

* Slideshow and fullscreen mode
* Rotating, zooming, flipping, resizing, and cropping
* Screenshot

I used it primarily for image cropping as I had to open gimp for every image I wanted to crop and that was bothering me a lot as it takes some time to startup.