Write this method on each view controller unless you have that plist entry.
Objective-c
-(BOOL)prefersStatusBarHidden{ return YES;}
Swift 3+
override var prefersStatusBarHidden: Bool { return true}
And don't forget to set (if you present a view controller by calling the presentViewController:animated:completion: method):
Objective-C
vcToBeShownWithoutStatusbar.modalPresentationCapturesStatusBarAppearance = YES;
Swift
vcToBeShownWithoutStatusbar.modalPresentationCapturesStatusBarAppearance = true