Scrubby is a tool to (eventually) edit sprites and other data in ROM files for OSX. There wasn't an all purpose tool for this for OSX and I missed YY-CHR so I started Scrubby. Currently Scrubby can just view tile data.
kalininskiy/Scrubby
OS X sprite viewer & editing tool. Supports SNES, NES, Gameboy and other formats to come.
Objective-C