UIRequiredDeviceCapabilities require dual cameras?

For now, and since you can't make an iPhone 7/Plus-only app for the store (yet?), I think you can only make it an option and code accordingly. If that's the only thing your app does, then you may be stuck unless you can expand it's overall functionality. Only App Review would know if they'd reject/approve, tho.

From the docs:

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Cameras/Dual Camera

Some iOS devices contain a dual camera—two separate back-facing cameras that can work together as a single capture device. When setting up a capture session on a device with an dual camera, you can choose to use only the wide-angle camera, only the telephoto camera, or the dual camera. Choosing the dual camera capture device provides behavior similar to the built-in Camera app—the system automatically chooses which camera to use during capture, and can combine data from both cameras to improve capture output.

The

AVCaptureDevice

devices

devicesWithMediaType:

• Call the

  AVCaptureDevice

  defaultDeviceWithDeviceType:mediaType:position:

  method, passing the

  builtInDuoCamera

  device type. If this method returns non-

  nil

  , the iOS device contains a dual camera. (If this method returns

  nil

  , you can call it again, passing the

  builtInWideAngleCamera

  device type, to obtain the default back camera.)
• Create an

  AVCaptureDeviceDiscoverySession

  object, passing the device attributes you want to use for capture, and enumerate its

  devices

  list to choose a device for your capture session.

When you use the dual camera capture device, Optical Image Stabilization (OIS), RAW Photo Capture, High Frame Rate (HFR) / Slow Motion Video, and most manual controls are not available. To use these features, specifically select either the wide or telephoto capture device. (For OIS, specifically select the wide-angle camera; the telephoto camera does not support optical image stabilization.)

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Additionally, you may want to file a UIRDC dual camera key request via the bug reporter, adding your report # to your thread for reference.