Beside releasing the Golden Master build of iOS 9, watch OS 2, and OS X El Capitan, Apple also released the first beta of iOS 9.1 and tvOS to developers.
While Apple talked about tvOS, its new OS for Apple TV, at its ‘Hey Siri’ event, it did not mention anything about iOS 9.1. The OS will likely be making its debut on the iPad Pro in November and will add support for accessories like the Smart Keyboard and the Apple Pencil to the OS. It is unclear if this new release of iOS adds any other major new feature to the OS or not.
As for iOS 9, its final build will be released to the public on September 16 alongside the final release of watchOS 2.
You can grab the latest beta builds of iOS 9.1 and tvOS from Apple through its Developer Center.