The Monimoto GPS tracker works great. Tested it today. It is a battery-powered device with motion sensor, GPS and sim card. When someone uprights the bike, it wakes up, calls a designated number and starts tracking any movement, sending regular position updates to the paired phone. Yet when you approach the bike with a fob in your pocket, or with the paired phone (bluetooth on) it doesn't send false alarm. The tracker device is small, easy to hide under the fairings.
My only problem was too much range. The device felt the fob even when it was in the pocket of my jacket hanging in the wardrobe in the house, maybe 10 meters and a wall away. Rendering it useless when at home. After some thought I wrapped the fob in one layer of tinfoil, that interfered with the signal just enough to solve this, but still deactivate the alarm when sitting on the bike. I felt good about the solution, then I saw that I can shorten the range from the app...
Wire-free, Anti-theft GPS tracker for motorcycles that calls your phone and sends GPS location coordinates if your motorcycle is being stolen.
monimoto.com