Wait wait, I've got a better idea.
How about a tool that edits ANYTHING in Harry Potter: Chamber of Secrets for the Game Boy Color? It is one of my, and many other's favorite games, and I was saddened when they did not release an RPG version of Goblet of Fire. So, why not make a hack of the GBC game, and turn it into Goblet of Fire, or a spin-off game? Just ANYTHING that can edit the ROM, like seriously, it has been seriously neglected.