The first free photo program I used was Photofiltre, and it remains the one I use most. It is really easy to use and does most things. For a number of refinements, particularly some “arty” ones and a great facility for rescuing badly exposed photos, I later downloaded Paint.Net.
Today I have started a new one: Photoscape. It is also proving useful and does a few (for me) new things.
Here’s one little experiment:
I won’t be doing that on the photoblogs, but there is potential here. 🙂