Yes, but not to a 1200 GS of the non-water cooled variety (into whose technical section you have materialised) or indeed to a GS of any sort. One is on a car (not a BMW) the other on a motorcycle that happens by happy chance to be a BMW. Both are completely different in operation, though ostensibly do the same job. Do they work? Well, the alarm sounds and text alerts appear on my phone, which is encouraging at least. I can also see my bike's position displayed on Google maps, which is nice. However, as I have (thankfully) had neither vehicle stolen I don't really know.
Like questions about lost jackets, why not cast your net wider into the pool of knowledge that is UKGSer? You have paid for a round, so drop into the pub or try the 'Gadgets and gizmo' section.