(commonly called Wii U USB Helper or 3DS USB Helper) is a third-party software tool that facilitates downloading, decrypting, repackaging, and transferring Nintendo Wii U and 3DS software titles (games, updates, DLC) to emulators (Cemu, Citra) or hacked consoles. Title Keys are unique cryptographic identifiers that unlock encrypted Nintendo content. Without the correct title key, downloaded game files are unusable.