"Why does Game Center not work on my sideloaded app?" is a question which gets asked a lot around our community and here's a topic to explain what's happening and ways to resolve this issue with sideloaded iOS apps.
The Problem
Every app on the App Store has a unique bundle identifier (a.k.a bundle ID) which Game Center recognizes & supports. On the latest iOS versions, Apple has prevented users from sideloading apps that have the same bundle ID as existing App Store apps, so we're forced to use a different bundle ID in order to sideload which in turn makes Game Center not recognize the app.
The Solutions
Use the normal iOSGods App when it is signed and working.
Purchase & use iOSGods App+. This works because this new limitation only affects free/normal Apple IDs.
Enroll your Apple ID to the Apple Developer Program and use it with Sideloadly or the Apple Developer Program Install option.
Use the app's own syncing system via their own account logins or via the social logins such as Facebook, Twitter, Google, QQ, Line & others. This makes it so we don't have to rely on Apple's Game Center. Example with Last Day on Earth app.
Use the apps as-is. We've been working hard and implemented various fixes to sideloaded apps, so even without Game Center, your progress will still be saved as long as you do not uninstall the app and overwrite it when sideloaded.
Jailbreak. You could have a device you can use specifically for this. Palera1n Jailbreak supports the latest iOS versions. When Jailbroken, you can install apps without having to worry about revokes, or Game Center. TrollStore & TrollStore 2 is also included.
This new Apple limitation has only been implemented starting iOS 13.3.x and higher. So if you have an iDevice on an iOS version lower than that, you should not be affected.
You may also like this topic