Pokemon GO adding Facebook account linking and login updates
Pokemon GO is in the process of rolling out support for Facebook account linking. Not only will the sign-in process be simpler, but the link also provides more log in options and helps preserve your progress across devices.
Players will be able to link their Trainer profile to your Facebook and Google accounts, and use any of those credentials to access the game. This means that if you currently log in with the Pokemon Trainer Club, you could link your Trainer profile to your Google and Facebook accounts, and then use whichever account you prefer in the future.
Linking profiles to a Google or Facebook account is simple. Just visit the settings and choose the platform you’d like to link.