Apple released the first beta of iOS 15.1 and iPadOS 15.1 to developers today. IOS 15.1 can be downloaded from The Apple Developer Center, or you can install the correct configuration file for OTA upgrades.
At the same time, Apple also released beta versions of watchOS 8.1 and tvOS 15.1. IOS 15.1 includes some features that were originally planned for iOS 15, such as SharePlay.
As an extension of iOS 15, the new system focuses on fixing bugs. In addition to iOS 15.1, Apple also released HomePod 5.1 beta, which adds lossless audio and Dolby Panoramic sound support to HomePod and HomePod Mini. HomePod beta software is invitation-only for developers.
Apple said earlier this year that it would not automatically push iOS 15 to users for a variety of reasons, noting that it would continue to provide security updates for iOS 14 after the new operating system was introduced. Users who are still using iOS 14 will see a choice of two software updates in their Settings, one for the latest version of iOS 14 with bug fixes and the other for iOS 15.
Apple also stopped signing iOS 14.7.1 codes, ending the demotion from iOS 14.8 and the recently released iOS 15.
Apple pushed iOS 14.7.1 in late July as a patch that fixed an issue where the Apple Watch could not be unlocked by iphones with Touch ID.
The patch also fixed a security hole that allowed an attacker to execute arbitrary code with kernel privileges. The security flaw was reportedly used in zero-click attacks deployed in NSO Group's Pegasus hacking tool.