I bought two Boomerang bike trackers a while back as well as upgraded to their 4G version the "V2". Unfortunately they aren't great at stuff like arming, disarming, etc... You can arm/disarm using bluetooth using Bluefruit, but the app can only do so through the 4G network it attaches to which can be iffy sometimes. The battery is okay, but not amazing, I have to charge it pretty often.

The things are pretty obvious and are intentionally so. They have an audible alarm that goes off if they sense movement and send a notification to your phone if they can connect to 4G (Iffy). I guess some Canadian city tried to run a bait bike program using them but no one would touch the bikes with an alarm. Personally I prefer to deter than to have to hunt down the thieves and retrieve.

By far the best way to prevent theft is to register your bicycle and encourage others to do so as well. I use Project 529: https://project529.com/garage

Police tend to not enforce bicycle theft, mostly because proving ownership is not usually possible due to lack of VIN numbers and registration. Having proof of ownership like photos, Project 529 stickers, and such is a great way to help police stop bike theft.