OBD2 Scanner/App: what sensors/values to monitor?

[SparkYellow]

Do any of you keep your OBD2 scanner on to monitor values not shown on the car's dashboard? I have a spare Android phone that is now doing that job. Besides coolant temp (194~214), ATF temp (188~208), battery/ECU voltage (14/13), there are many more sensors to choose from the app. I understand that not all of them are available for my specific car/connector. What are some other values that are useful to monitor and log? It's a 2017 CX-3 that didn't need extra attention until this year (after 153K+ miles). Thank you!

 

[Speed3.5]

Which obd2 scanner/app combo you're using, I'm thinking to do the same for 16' mazda 3.

Temps and voltage are easy to monitor, most engine parameters are best data logged then reviewed afterward until you find a set of parameters to review live.
It gets cumbersome to review live engine parameters constantly.