This will be arriving on your phone over the next few days, or grab from the play store when available.
This release removes all Facebook integration. Facebook sign-in has been dropped from the web site already, and from this release, removed from the Android App too. The Apple App will follow.
For Android, new users should use Email/Password or Google sign in.
Facebook login is currently non-functional over all clients, so this should not impact any active users.
If you are still logged in from a Facebook account, it is necessary to add an email address to your account right away to retain the ability to login. Send feedback otherwise.