GIMP is a free program for such photo retouching, image composition and image authoring. Essentially it's the closest thing to Photoshop you can get for free.
GIMP vs Adobe Photoshop Elements opinions
In times your wallet is empty we need programs like this to be able to share and who knows, to sell our knowledge. In other words; to get you back on the track again. ;)
Can do exactly everything that Photoshop elements can, actually even more than what ps elements can do
Krita is a professional Free and open source (FOSS) painting program. It is made by artists that want to see affordable art tools for everyone within concept art, texture and matte painters, illustrations and comics.
MyPaint is a fast painting program with an emphasis on full-screen use. It lets you focus on the art instead of the program. You work on your canvas with minimum distractions, bringing up the interface only when you need it.
Glimpse is an open source image editor based on the GNU Image Manipulation Program. The goal is to experiment with new ideas and expand the use of free software.Discontinued
The Glimpse editor has been discontinuedSource: https://glimpse-editor.org/posts/a-project-on-hiatus/
CinePaint is a deep paint application that edits EXR, DPX, 16-bit TIFF, JPEG, PNG and many other types of image files. CinePaint is available as a native application for Linux, Mac OS X, and BSD.This app doesn't have any features at the moment.Discontinued
The development is discountinued since 2013-05-06https://sourceforge.net/p/cinepaint/activity/?page=0&limit=100#599c65d15fcbc926952bcea9
gpaint (aka GNU Paint), a small-scale painting program for GNOME, the GNU Desktop Environment. gpaint does not attempt to compete with GIMP, it is just a simple drawing package based on xpaint, along the lines of Microsoft Paint.