Resolution shows the usable screen resolution and the resolutions of the available cameras of the device.
This app requires the right to take pictures in order to query the properties of the cameras. However, the app does not take pictures or save any data.
The number and resolution of cameras available for third-party apps depends on various conditions. Third-party apps access the device's camera via the camera api, or as of Android 5.1 via the camera api-2. It depends on the manufacturer of the device, the Api used, the Android version and the update status how many of the built-in cameras and with which resolutions can be used.