Are you sure this actually works? My understanding is that iCloud backup is specified by the user per app (can default to on). Going into my iPhone->Settings->

Are you sure this actually works? My understanding is that iCloud backup is specified by the user per app (can default to on). Going into my iPhone->Settings->Authenticator there are no iCloud settings and iPhone->Settings->iCloud shows lots of apps but Authenticator is not one of them. I have iCloud backup on, have switched through at least 2 phones (as in 6+->10->11) where I have Google Authenticator on. The new phone never had any of the Authenticator codes after restoring yet all the other apps restored their data.