If your iPhone has hung up on the Apple Screen when booting, perform a battery-cycle reboot, or a "reset," to get the device to fully shut down and load iOS again. Resetting is different from ...

From the home screen, hold both the Power and Home ... might cause your iPhone to get stuck in a loading cycle. Soft reset the device, and then check for updates to iOS by tapping "Settings ...

Additionally, PCMag also gave this a go and it resulted in the screen turning black, then pausing with an iPhone loading screen for a few seconds, and then relaunching on to a locked home screen.