I've just reviewed this sub-£60 OBDII tester on Amazon, reduced by a tenner on Prime:
https://www.amazon.co.uk/scanner-Launch-Creader-Diagnostic-Functions/dp/B06W5V24JN/
I've had a few cheap ones like bluetooth OBD adapters and cheap hand held code readers/clearers, but for the price, the live data, colour screen and graphing functions give this the edge.
No connection, just a happy customer and serial Amazon reviewer
HTH
Nick