My friend is a mobile mechanic and he said you can access the Onboard Diagnostics with no problem on any car you want. You just need a SnapOn scanner or similar brand with the appropriate adapter for whatever car you are dealing with, and the scanner firmware must be updated enough to accommodate the year model you are working on. That's it.
You can go to Advance Auto and they will do it for you for free. Some brands have proprietary systems though, VW/Audi for example.
As car manufacturers are becoming more and more scared of their cars being hacked are they moving fast to encrypt all communication on the data buses in the car. Soon these kind of apps and third-party software will not work anymore. You wouldn't want a hacker to mess with the auto pilot of your Tesla.
Time to trade it in for that new bugatti Chiron for a business write off. https://www.yahoo.com/news/tesla-raised-supercharger-rates-across-222100014.html
I bought one of these at Harbor Freight. So far, so good. I kept getting "Service Engine Soon" light. Had to replace both upline O2 sensors on my F-150. Btw, I remember setting the points with a book of matches in the old days. Cars are WAY better today...no comparison.