I'm skeptical, but if you have an Android Phone there's plenty of apps out there like BLE Radar and BLExplorer. BLE Radar doesn't work on my current phone (phone's too new), and BLExplorer doesn't necessarily provide a lot of useful information, but it does provide device MAC addresses, which could lead to some interesting leads.

BLE Radar: https://f-droid.org/packages/f.cking.software/

BLExplorer: https://f-droid.org/packages/org.ligi.blexplorer/

/u/artyjulia suggested Bluetooth scanner from this site: https://apkpure.com/bluetooth-scanner/com.bluetoothscanner

I'm skeptical, but if you have an Android Phone there's plenty of apps out there like BLE Radar and BLExplorer. BLE Radar doesn't work on my current phone (phone's too new), and BLExplorer doesn't necessarily provide a lot of useful information, but it does provide device MAC addresses, which could lead to some interesting leads.

BLE Radar: https://f-droid.org/packages/f.cking.software/

BLExplorer: https://f-droid.org/packages/org.ligi.blexplorer/