I've already got someone translating it to Spanish, but you can give it a shot if you like.
There are no other programs for creating the graphics, but why would you need them? I'm kind of insulted, heh.
You can't just edit the (EGA) background pictures like you would in normal paint programs due to their file format. You need to edit them in the manner that SCI Studio edits them. If there were other programs, they would operate exactly the same as SCI Studio's picture editor.