This really wouldn't work for phones. The accelerometer needs to be very high precision, which is why it only works on very recent Apple Watch models. The accel

This really wouldn't work for phones. The accelerometer needs to be very high precision, which is why it only works on very recent Apple Watch models. The accelerometer also needs to be running all the time, even while the main processor on the device is sleeping. Also you need a reliable way to detect that the device is firmly attached to a human; it's not acceptable to call 911 when a phone falls on its own.