Are there any 2D texture mapping programs out there?

I am just getting into animations and have finally completed my first 2d texture map. BOY WAS IT HELL. I am not good with using paint programs and managing the pixels and copy and pasting the image side by side trying to get it all aligned. So i went searching for a program that might have some kind of framework to streamline all that and simplify it for someone who enjoys code, but is a little iffy on his paint skill.

If any of you guys know of software that is designed to help people create their own sprite atlas/maps. I would sure appreciate the suggestion.