I was facing same issue when I install Application in 2 types of devices iPhone 6 (Standard mode) and iPhone 6 (Zoom mode) but later on I try to catch the height and width of the iPhone when it launch.
in your ViewController.h class in viewDidLoadmethod try to check the height and width in console.
NSLog(@"width %f, height %f",self.view.frame.size.width,self.view.frame.size.height);
By checking this you can get difference between Standard and Zoom mode.
From the Vizllx answer u can also check like below what I tried.
UIScreen *MainScreen = [UIScreen mainScreen];
UIScreenMode *ScreenMode = [MainScreen currentMode];
CGSize Size = [ScreenMode size];
NSLog(@"width %f, height %f",Size.width,Size.height);
Thanks.
