I just bought one of these based on a recommendation from a Youtuber channel on flipping cars.
Once you pair the OBD2 dongle/reader to your phone you can plug it into any car. It has a fair about of detail and is apparently a perpetual license with no additional data fees.
Pairing to my iPhone was a pita requiring some strange and still unknown sequence using the customer support. It is fickle to say the least needing some sequence on dongle on / dongle off/ dongle on process fro it to detect the iPhone for pairing.
It all works now and after this initial difficulty, the dongle is detected and has reconnected each time I plug it in. It works with a 2000 E-350 and 2002 E-250 and 2004 MB C-320.
At least one of the reviewers is from a used car dealer that might use it on 50 cars a day looking for error codes.
When I tried to clear the codes on the E-250 it hung upon so I'm not sure about that, but generally very useful and convenient for such a scanner if you don't have one yet.
This is mainly a software product, with a $20 dongle so given al future Software updates are free it is a pretty good deal. Almost all S/W business models evolve to subscription-based payments so this is still a good deal for the long term.