There's a great deal of convenience that comes with using Automatic, just so long as you're fine with beaming every trip you take up to the company's servers. The app can tell you what routes you've taken, where you're parked, how you dive, and what you need to work on in order to save gas. It's a nifty tool, and while there are some significantly more affordable alternatives such as Dash out there, Automatic is the best option for someone who doesn't want to deal with picking out their own OBD-II device or wrestling with a less polished interface. But to use it, you need an Automatic Link.
This dongle plugs into your car's data port, and it usually goes for $99.99, significantly more expensive than the ones you can find on Amazon and elsewhere. But it's the only OBD-II device you can use with the Automatic app, so you have to make the plunge if you want to use this particular service. Fortunately it's currently going for 20% off. Not only that, you can save an additional $15.99 by applying the coupon code ATP2014.
I've written a pretty in-depth review of Automatic if you want to know what your money will get you. I've also provided a thorough look at the nearest competition if you rather not spend all that money. Though at under $70, this discount makes Automatic competitively priced compared to some of the better adapters that Dash recommends.