Follow up: One big plus for BlueDriver, it has a built-in data base of the DTC (Device Trouble Code) that explains the code meaning in plain English.
If you can live with or use a wired scanner, I am very happy with the ScanGuage II. Available on Amazon or at most Auto Zone stores. Like BlueDriver, it is a US based company, so tech support is speedy and effective. ScanGuage natively supports engine codes, but just displays the nemonic (like P0002); you have to look up what that means. The device supports expanded data that ScanGuage calls "XGuage". The web site lists XGuage codes by car manufacturer. The folks at ScanGuage responded to my request for CVT temperatures for a 2012 Maxima. Though not published on the web page, I programmed the supplied code and got the information I needed. I will gladly relay that code to any who need it. Nice job, ScanGuage!