More than that. I think you can use it to do things like open your garage door as you approach the house, etc.
I already have an app for that, came with my garage door lol
I get the "pitch" and to me it's the same snake oil as other fuel saving devices... it'll save you hundreds in fuel costs! I recall another similar device a few years ago that would warn you if you stopped to fast, took off to fast etc... all to save you fuel and hundreds at the pump! lol
Code readings can be had at any auto parts store for free but I don't think the "average" driver would know they can get this done as well as some of other free testing services that auto parts stores offer.
most the errors it may toss up like Gas Cap loose, I think every modern vehicle has a smart enough instrument panel to show these type of messages.
Hell - I already get tracked on all my trips via my phone lol, why would I want another device piggy backing off my data plan? I'm not keen to offer up my travel data to build up another database for that information to be sold at a premium. The toll roads already have most my data lol