This is an odd addition, for it is not really for authors, which is who our “Resources” section is about. That is, unless you are also an illustrator or know one. Either way, you will want to check out Krita, a digital “painting” program.
While we were impressed with the application itself during a limited test run, when we saw the “gallery” at its main site, that was the clincher. Those of us who are would-be to professional authors would love to have one of those artists do a cover for one of our works.
Fully capable, open source, and free, not to mention cross-platform, it will integrate with most common to industry level touch-sensitive pen & tablet hardware. Some plugins are available as well, which you can find by looking carefully at the application’s site(s).
Oh, and like we said, you have to see the gallery for what this application can do in the hands of someone who can use its full potential. Start off by visiting “Resources: Graphics.”