Just 24 hours after the public release of iOS 12, Apple has kicked out the first developer beta of iOS 12.1. It re-introduces Group FaceTime and includes a number of hints about new iPads that we may see this fall.
Updated 09/20/18: iOS 12.1 beta 1 is now available for public beta testers.
Developers can head developer.apple.com to download the beta or add the beta profile to their devices. Non-developers who want to be part of the public beta test can head to beta.apple.com using the device on which you want to run the beta, where you can sign up and download a beta profile. If you still have the beta profile installed after upgrading to iOS 12, your device will download it automatically as a regular iOS 12 update.