Mine does everything Skytag's does... as well as allowing real time tracking from a web site, disabling the vehicle, tilt detection and so on...
Prices are negotiable to some extent and I'm happy to develop one off sensors or triggers when required.
Apart from that little bit of SPAM!
When you look out for a tracker there are a few things you should consider carefully. These do vary from device to device and can make a substancial difference to the device's performance.
Work out what you really want from the device before you start shopping. Sounds stupid I know, but there are so many different services available that it is easy to get bogged down... Do you want it for simple after theft recovery, if so then you won't need the minute by minute reportsand all the extra cash that will add to the price.
Do you want to be able to take action on the vehicle like disabling the engine, killing the fuel supply, triggering alarms, firing a spike through the driver's seat - or do you simply want positions.
Make sure that the device will operate on different networks. some devices work OK in UK but fail miserably... Rusty Rhinos took ours down through the Sahara twice and I was surprised just how good the coverage was.
Find out which GPS decoder is built into the unit... the more channels the better and more reliable the fix.
Is the device robustly built into a metal case or a piece of japanese plastic...(there are more and more chinese/japanese devices coming onto the market at a price of about £50; but the quality is reflected in the price.
I could go on, but I hope these thoughts are useful.
Without trying to vye for business... I would be happy to answer any queries about these systems... I personally believe that when they are properly installed they are a fantastic security measure.