Board Thread:General Discussion/@comment-26988724-20141031214436/@comment-201.204.112.72-20141118202711

Use: you get a code, friend's code, whatever, then in game there's an event bar on home screen, at the bottom, when you see the nevil invite thingie, you click on it, enter the code you want to use.

Find: welp, in here, on reddit, pretty much searching google for invite codes to use, post for others to use yours.