Reading OBD II codes
 

I got a cheap OBD II bluetooth interface off ebay and downloaded the Torque app on my Android tablet. Also paid extra for the Hyundai-specific app extension.

The setup works great on both my Entourage (and my Honda Fit) so I can recommend this setup based on experience. So far, I've only read codes, I haven't tried monitoring engine parameters when the vehicle is running - mostly because I can't drive the vehicle and look at all the cool things the emission control system is doing at the same time.