In the past few years, we have covered plenty of anti-hijack iPhone compatible immobilizers for cars. The BT-26 happens to be a Bluetooth proximity immobilizer for motorcycles. It can disable the engine when connection to your phone is cut off for more than 3 minutes. It automatically arms when the ignition key is off.
The device also has an override valet mode just in case your phone loses its power. More information is available here.