My ZTE N9120 cannot control game apps that have control flying items. Tried resetting calibration, but I can't find calibrator reset on my device.
There is no built-in application to calibrate the sensor. You will have to use a 3rd party application for this procedure. Access Google Search and download DHD Proximity Sensor Recalibrator. Transfer the APK file to your phone and install it. On the XDA Developer's post you will also see calibration instructions. This is the only way to calibrate the sensor for this particular phone.