fang is a small proof-of-concept application to find non discoverable bluetooth devices. This is done by brute forcing the last six (6) bytes of the bluetooth address of the device and doing a read_remote_name().
You can download it from the following link: https://packetstormsecurity.com/files/download/31219/redfang.tar.gz
Source: https://packetstormsecurity.com/files/31219/redfang.tar.gz.html