This is the only device like this that has its own cellular connection and GPS.  You only need to have your smart phone in the car for initial set-up.  Unfortunately, you can only receive the data from the Key on your smart phone, since there is no web page or internet portal, but that is the only real complaint that we had about this service.Set-up was quick and easy on both our 2012 Toyota Prius V and our 2011 Subaru Legacy.  The system also lets you move it between the two cars without needing to buy a second service account.Some of the reviewers are complaining about the $100 a year price being high.  Considering the Zubie Key has its own cellular data connection, this price is very reasonable.  It wouldn't surprise me if they are losing money on their first few thousand customers because of the cellular data costs, until they hit a breakeven point on their other expenses.  Compared to other options that don't have their own cellular connection and GPS, this might be the best value ever in parental aids for teenage drivers.  Considering the damage to property, lives, and their future that teenage driving can cause, this is the best protection you can buy for when your teenagers are driving.In my opinion, it doesn't matter how much you trust your kids, driving a car is too huge a responsibility for young drivers to do it unsupervised.  Not having a tool like this Zubie Key Service installed creates enables temptations to drive recklessly or not follow your rules that are too big for even the most responsible young-adults to handle.Compared to services like this from Ford and other car manufacturers, this is cheaper, more effective, and easier to use.  I found it simple to use and feel that it covers all the bases needed for young drivers.  No, it doesn't have a Breathalyzer or a direct way to tell you if the cell phone is being used, but by monitoring things like hard braking and fast acceleration, it indirectly gives you this information.Because of the lack of privacy protections, I will never drive with this installed again (beyond a few days of testing it).  I pull it out of the plug as soon as I get in the car.  Conversely though, our teenage drivers will never operate one of our cars without this installed, now that we have it.  Our new rule is that driving our car requires the Zubie Key to be installed.I strongly recommend that all parents of young drivers get this.  I wish that my parents had it back when I was a young driver, because only luck (or divine intervention) prevented me from ruining my life the lives of others.  As for using it to monitor yourself, I strongly discourage it.  Being tracked by your cell phone is bad enough.  Do you really want to give them another way to take your actions out of context and put your Liberty at risk?One last comment.  You might be thinking that I don't trust kids, or have something against teenagers.  I don't.  I believe that kids of all ages should be given a very long leash (figuratively) relative to their age.  Despite this trust, and desire to give freedom, the reality is that driving a car is the most dangerous and life altering thing that a young adult does.  To not use a tool like this to assist them in their newfound responsibility is missing out on a great opportunity to coach, teach, and protect.