The video doesn't appear to be working, but in the description, he claims that there are no wires involved and it uses bluetooth to talk to the cars OBDII??
Yes, you need a BT reader. I got mine on eBay for $30. The developer is constantly updating the app and it works on my 97 xj with my 4.7 stroker. Plus, this is just the tip of the ice burg of what my Droid Incredible does. It even will reverse the gauges on the screen so you can put in a car mount backwards and have a heads up display!