REFrostedViewControllerUIKitIsFlatMode is NO, even on iOS 9, if REFrostedViewController is the main storyboard's root view controller.
UIApplication.sharedApplication.keyWindow is nil at this time, so it goes into
[[UIWindow new] performSelector:@selector(tintColor)] != nil
However, tintColor is nil at this time, regardless of appearance settings, because the app delegate hasn't yet been instantiated.
REFrostedViewControllerUIKitIsFlatMode is NO, even on iOS 9, if REFrostedViewController is the main storyboard's root view controller.
UIApplication.sharedApplication.keyWindow is nil at this time, so it goes into
[[UIWindow new] performSelector:@selector(tintColor)] != nil
However, tintColor is nil at this time, regardless of appearance settings, because the app delegate hasn't yet been instantiated.