I'm a bit of a technophile, and not easy to please when it comes to new applications for existing tech. But this little gizmo is doing quite well. It was easy to set up. The app is very easy to use. I get the information I want without a lot of clutter. Frankly, I can't imagine having driver age kids without having this or something like it installed in the car. I recommend it whole heartedly. I'll update my review in a few months to see how it holds up.

I purchased this unit so I could better keep track of my wife and my 16 y/o daughter when she is driving. We live in an area where cell phone reception is fairly spotty and the road which leads to the main highway is very bad. It has narrow lanes and VERY sharp curves, something out of a horror movie. If one of them were to wreck and couldn't get service I wanted to know right where to find them. I decided to take a chance on this unit and sure enough it works great. It doesn't lose track of the vehicle. I can monitor exactly where they are at and how fast their moving. If the vehicle stops for any reason where it wasn't planned and I don't get a call I know something is wrong and I can respond or call the highway patrol myself. It really gives a peace of mind.

The unit does tell me when the engine is started, where the vehicle is at, how fast it is moving, etc. I have yet to receive any alerts for hard breaking or harsh acceleration. I also have not had a chance to test the OBD part of the unit because I do not have a check engine light and I am not in a hurry to get one.

My only issue so far is I can't figure out how to set the geofence alerts. I want to set a geo fence so I know when/if my daughter goes outside a planned area but on the app and on my PC that option appears to be missing.

Overall though the unit is working as I had hoped. It is well worth the $23 a month.

Very disappointed. It worked very well for a couple weeks and then the tracking started being super flaky. I was under the 1mn plan but I would only get update every 30mn or every hour... when it worked. I contacted the company and unit started working again as expected (even though company did not acknowledge the issue) but after a few days the tracking started to be buggy again.
Also, if I didn't drive the car for a couple of days, my mastrack unit would drain the battery.

Maybe I got a buggy one... but for the cost and the lack of support, I felt like I ended up throwing money away.
I just switched to a syncup drive from tmobile (new as of november 2016) which does the exact same thing, cheaper and more accurately (and doesn't drain my battery).

This device is working as advertised, however both the web portal and the mobile application need some serious work to make it appealing and worth the buck. I had to contact support several times to claim my free month membership. We bought the GPS tracker for my daughter on her first year in college, just so we can have peace of mind. I told my daughter about the device when I installed it, and I also added her to the notification list, so she is aware it's not a hidden tracker to spy on her, but it's rather a safety device. She is very cool with it now..

the device just plugs into the OBD plug

This unit is accurate to within a few feet. Our property straddles two different addresses, if I park on one side of the property line or the other, it correctly identifies the addess. It shows EXACTLY where I parked within mall parking lots.

When I got the product, it was very flaky, kept losing its connection and stopped reporting. It was unclear whether it was the unit itself, or some interaction between the unit and my car. Although I purchased the unit from Amazon, I called MAS, and exchanged the unit for the model with the battery (and requested Verizon cellular, which is better most places I travel). The 2nd unit has worked flawlessly since the moment I plugged it in (although I did have to request that they initialize the unit, which they told me had already been done - it had not, but they resolved the issue within minutes of my contacting them by email).

MAS was super quick and super responsive throughout trying to make the 1st unit work, and then through the replacement process. They accomodated me in every way possible.

Support is excellent, although voice support is closed on weekends, email support is still available and very rapid. In short, my experience could not be better