Bluehawk

BlueHawk helps you to find your lost Bluetooth devices by measuring the approximate distance between you and your lost device. When you move, BlueHawk will calculate the distance again, and you will find your lost device easily.

You can also define automation rules so when your device enters or exits a range - you can send an alert notification

or start phone Video and audio recording , which can turn any compatible smartphone into a smart security "camera" based on proximity instead of visual motion detection.