An is a third-party software tool or web-based utility designed to decrypt, read, modify, and re-encrypt these save files. In short, it is a God Mode for your save data .
You need to test a specific late-game mechanic for a YouTube video, but you don't have a save file near that area. Instead of playing for 10 hours, you use the editor to teleport your party to Map ID #045 and unlock the required story switches. rmmzsave editor