So you are worried about someone stealing your bike? This Smartphone Alerting Bike Alarm can help. It is a bicycle alarm that alerts you when someone is trying to steal your bike. It looks like a regular bike light that attaches to the seat post but has a motion sensor that detects movement and sends an alert to your smartphone.
The alarm has built-in GPS functionality to allow you to track the bike’s location on your phone. The device has a working range of up to 295′ away. The rechargeable battery lasts up to 2 weeks on a full charge. Just bring your iOS/Android device, and you are set.