Add leaderboards to an app version - Configure Game Center - App Store Connect - Help - Apple Developer

Leaderboards can be added to your app version once configured. For information, view Configure leaderboards.

Everything you need to know about Game Center

7 - IOS Leaderboard - GameSalad Customer Service

Integrating Achievements and Leaderboards into Your iOS Game Using Game Center

Configure leaderboard sets - Configure Game Center - App Store Connect - Help - Apple Developer

Leaderboards SpringerLink

Game Center Leaderboards!

Bring Recurring Leaderboards to your game - WWDC21 - Videos - Apple Developer

Add an app to a group - Configure Game Center - App Store Connect - Help - Apple Developer

Using Google Play Services Leaderboards in Unreal Engine Projects

How to integrate GameKit — iOS. Make your game stunning with these…, by Abedalkareem Omreyh, The Startup

Game Center Overview - Apple Developer

Game Center leaderboard and achievements not live - Unity Forum

We Hacked Apple for 3 Months: Here's What We Found