I got to this forum today because I'm trying to figure out how to add a maintenance log. It still says I've never had an oil change. I'm still looking for that answer, but since I'm here ...
I never bother with the Uvo app except to download the monthly health report. I tried to use the Parking Minder when I first got it, but it's too manual, so I never remember it. Uvo cannot be used at the same time as Android Auto, so if you're using Google Maps or anything, might as well use that to mark your location.
The dealer appointment feature is also a waste. It just initiates a call-back from the dealer. I can schedule an actual appointment by going online. (A data connection is required to use Uvo anyway.)
I did find today what looks like it might be a cool feature, but I have no idea how to use it or what it really does. Under Additional Info for the parking minder, it says meter time, alarm time, and space for two photos and notes. Sounds like those might be handy things to use, but there's no info on them that I have found. The MyCarZone might be cool if anyone else drove my car.
Maybe it's better if you have the nav system?