Ryan Christoffel has been testing Sign In with Apple in some beta versions of apps this summer. Using it is as easy as Apple said it would be. And the feature that I hoped would be included will arrive too: Converting your existing logins to Sign In with Apple.
Although Sign In with Apple is mainly beneficial for new users who don’t yet have an account for a given app or service, with the system Apple has built, developers have the option of letting existing users convert their accounts to Sign In with Apple for its convenience and security benefits.
I hope there will be widespread adoption of this. Another thing I wondered: If some companies complain that iOS 13’s location feature is anti-competitive, what will they say about Sign In with Apple?