Duolingo waited until the last possible minute and then
removed all their social sign ins instead of adding Sign In With Apple. I guess we know where they stand on user privacy.
Delete!
Update: Duolingo got sneaky and went around the App Store approval process. While they removed Facebook and Google sign in on the login screen, they buried it deep inside the settings as Connected Accounts. Sign In with Apple is not an option.
Between this and the secretive clipboard copying, I’m starting to realize that not only are there a lot malicious developers, but App Store reviewers are incompetent and easy to fool.