Free Software that I rely on. One per day, I guess.
Day 2:
Gnu Image Manipulation Program
Known as #GIMP or as #GnuIMP by those who don't like the other name.
This is my go-to tool for basic image processing of photos and images for publication. It's a pretty common workflow for me to crop and/or enhance photos in Gimp and then load the output into Inkscape for layout work.
Also, FWIW, I learned it before I learned Photoshop, which frankly seemed kind of like a backward step to me, particularly in the way that Photoshop filters never seemed to have any controls (at the time -- this was 25 years ago and I haven't used Photoshop since then).
Which fuels my general belief that terms like "more intuitive" or "more powerful" are mostly a function of what you are familiar with.
It's one of the earliest graphics creation software packages I learned on Linux, and so it's become so much second nature that I hardly think about it anymore.
These days I use it all the time to crop and rescale screen captures, so I've attached one of cropping a screencap of itself.
