While Apple hasn’t detailed the changes publicly, the company is planning what appears to be a major, undocumented overhaul of its AirPlay protocol with iOS 9 that should make the framework for streaming video and audio content between devices a much smoother experience for both users and developers. It is, however, breaking many screen mirroring apps in the process and forcing developers to scramble to implement workarounds ahead of the launch of iOS 9 on Wednesday and the new Apple TV in the coming weeks.

Perhaps the best example of these apps is Reflector from developer Squirrels. The app utilizes AirPlay to allow cross platform wireless mirroring from mobile devices to Macs, PCs, and other devices with the app installed. The developer first brought the change to our attention and warns that developers will have to follow in its footsteps to implement a workaround that will allow screen mirroring apps to continue functioning after iOS 9 is released… 

“What Apple did this time around with iOS 9 updates is make a wide-sweeping change to underlying protocols that power AirPlay,” Dave Stanfill, president and CEO of Squirrels explained. “A lot of the pairing setups (like how your mobile device interacts with a receiver) have changed. A lot of the exchanges between an iOS device and an Apple TV or any of the receivers have changed. The actual mechanism through which a mirroring connection is established was entirely overhauled. So, many underlying AirPlay components and protocols are entirely different in iOS 9. Not only at a security level but also with the way the two devices talk to each other.”

While the changes won’t affect app developers simply using AirPlay APIs for offering users the ability to stream from within an app to an AirPlay device like an Apple TV, it will break many screen mirroring apps that tap into the AirPlay protocol for screen sharing like Reflector. The apps are often used in education, enterprise, and within the tech world for things like screen recording and display mirroring to devices not supported by Apple.

Though developers of screen mirroring and streaming apps piggybacking on the protocol will have to implement workarounds to avoid issues with the changes in iOS 9, the overall changes appear to be a move by Apple to vastly improve device pairing and in the process improve the overall AirPlay experience across devices. The developers at Squirrels explained:

We discovered AirPlay has improved security, it’s faster and it improves overall performance. Using some of the new security features Apple implemented, the whole stack moves a lot faster. It allows for more interesting things like one-time pairing. That means less battery drainage and faster encryption and connection… This protocol is designed from the ground up for existing wifi, wifi direct, AWDL (Apple’s own wifi direct used for AirDrop and other features), Bluetooth, and even USB CarPlay and QuickTime. It is clear Apple sees a future of pairing all of your devices together in one easy to use network.

It’s possible Apple’s motivation for the changes to AirPlay and device pairing is related to the Apple TV acting as a hub for remote access to HomeKit products and the new Apple TV’s support for third-party gaming controllers. But the end result should be an overall improved experience for AirPlay and device pairing with the new Apple TV. “You could pair your iOS device to an Apple TV and never have to go through the full key exchange again. Once it’s paired, it’s paired,” the Squirrels developers explained, “Apple set the underlying foundation to “set-it and forget-it pairing” whether it be with your car, a set-top box in the living room, that sort of thing. That’s the fundamental reason they changed that protocol, we think.”

After implementing a workaround for the changes, for which Apple hasn’t released any documentation to developers, the result is a Reflector app with significant performance improvements, the developers told me. But until developers implement a workaround on their own, users that heavily rely on a similar screen mirroring app for iOS should consider holding off on updating until the app has updated for iOS 9.

iOS 9 is scheduled for release on September 16.