Want to make cheats for CFW 4.21 or greater? This new app by Medo might do the trick.

For newcomers to the scene, sometimes wading through several different tools to create the cheat you want can wind up being a little bit of a chore. Instead, this app tries to bring the entire process together by using as few apps as humanly possible. As its name implies, EBOOT Modifier changes you game file and then let's you rebuild it into an installer within the same GUI. The developer has a lot to say about this one, so I'll let them explain it below! Full instructions are included in the README as well!

It is here to allow people to make packages or modify eboots for games to add codes. Most people become very confused trying to make packages using CMP Auto Tools or other tools to decrypt a game's eboot and then re-encrypt it to install a package or replace a copy of the game's eboot to play with codes. This should solve that problem. It doesn't make modified eboots for firmwares that aren't 4.21+, so you users that are still on 3.55 just stick with the cracked version of CodeUnique.