It may seem trivial, but usual:

[[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationFade];

is not working, nor:

[UIApplication sharedApplication].statusBarHidden = YES;

Now everything is simplified and minimalistic, so all you have to do is new key in your plist file named View controller-based status bar appearance and set its value to NO:

Xcode plist file