I opened my project in Xcode 7 beta and I am getting the following warnings which I do not get in Xcode 6:
All interface orientations must be supported unle
This is because Apple has added multi task ability in iOS 9. All you need to tell Xcode is that your app require full screen.
Add the UIRequiresFullScreen key to your Xcode project’s Info.plist file and apply the Boolean value YES.
To read more about it in general.
https://developer.apple.com/library/ios/documentation/WindowsViews/Conceptual/AdoptingMultitaskingOniPad/index.html
By default the Device Orientation only enables Portrait, Landscape Left, and Landscape Right. You need to enable the Upside Down as well.