Apple Login is a new login system that Apple added to iOS in 2019. It allows users to login to Apple Apps using “Sign-in with Apple”. It uses the same authentication methods that the App Store uses and provides developers such as ourselves ways to implement this without as much work as usual.
Usually when we build apps a login system is needed and often times that means creating one as well. One that is supported by both iOS and Android, usually controlled by a centralized server backend. This extra work adds cost to a project which is clear why Apple wanted to simplify this process. The problem is Apple Login only supports the iOS platform meaning that something still needs to be done for the Android platform even if you implement Apple Login.
If we targeted just iOS on a project Apple Login would certainly be the best approach. But because iOS and Android both need to be supported most of the time it leads to ongoing issues. Since you still need to support Android a login system is needed there. Thus either a custom login system rolled from scratch or something like Facebook login or Google Sign-In is used. This is where the issues come in. The issue is the App Review requirement from Apple that if you implement any alternative login system such as Facebook then you must also implement Apple login. The only time an app doesn’t have to implement Apple login is if you have a custom login system created from scratch or have no login system at all.
This extra work of adding Apple Login is leading to some customers to choose not to add in alternative login systems such as Facebook and Google Sign in the first place. Or customers decide in some cases to remove these alternative logins from their existing app to avoid having to add Apple Login at all to pass their next App Review. Overall Apple login is a great idea but the outcome of it has been mixed for our customers. This is because Apple Login only supports iOS and most of our apps support more than just iOS leading to ongoing issues.