[bakakid]

I think this one applies: Aseprite pixel art/animation editor. The source code is free to use on github, but if you dont know how to compile it, then they also sell it ready to go for most operating systems.

as a student, i liked the idea of getting it for free, but couldnt figure out the compiling (im an illustrator/designer that dabbles in code, but not much at all) so i footed the ~$20 to be able to use it.