I can tell you what I did.
This guy showed my how to use the free Llama app.
https://youtu.be/RUHSOtlil7o
...which was a little hard to figure out at first, but I got it.
Then I bought this at the video's suggestion and it's great.
https://www.amazon.com/.../dp/B006NZ...f=sr_1_fkmr0_2
In the reading I did I found bluetooth to be best. You can find some of these for really cheap, but they will lag and I didn't want that. Mine is super fast. For instance when I have the car warm and then turn on the heat I can watch the coolant temp gauge drop a few degrees almost instantly. My tachometer revs the same as my analog gauge etc.
I still have to actually wire the thing up to F2 in the fuse box, but when I do it will turn on automatically, link the bluetooth and go right to the dashboard program that came with my OBDII link MX. Then When I shut off the car, the phone will shut off automatically as well.