Fever requires you to have either a Facebook or a Gmail account to log in the app. We use this connection to discover your interests and, thanks to this, there is no need to fill out lengthy forms to offer you the events that fit you best.
Take into account that Fever is designed to use only one profile on each device (mobile phone or tablet). In the case that two Fever profiles sign into the same device (New Version), you will not be able to redeem vouchers from any of them. Signing in with Facebook and Google interchangeably will create two different accounts and, hence, you will need to delete one of them: you can do so from the "Preferences & Legal" section from your app, clicking on Delete Account. (Remember that all your details associated to that profile, even your tickets, will be deleted).