When your iPhone is acting as a Wi-Fi hotspot or there is an ongoing phone call, iOS will show a status bar right below the standard status bar at the top. iOS will automatically resize the current view's height to compensate. Your app needs to be ready to handle this by setting the autoresizingMask property of your views appropriately. You can simulate the appearance of the in-call status bar in the simulator using Hardware > Toggle In-Call Status Bar.

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