To answer your question, yes you can use an iTouch or iPad as well as the iPhones.
We use WIFI as it is a much stronger signal and much faster.
Our app is free, go to our website and read the instructions and you will see our user interface is unmatched. You never have to leave your main screen or go into submenus to change any gauge parameter. We allow you to set up 3 different screens anyway you like and access them via single finger swipe.
We have been doing wireless data longer than pretty much anyone. We were the very first with the iQuad stuff and our apps have remained well ahead of everyone else.
Its free, go download it and play with it. Also we have a 30day satisfaction guarantee, try it and if you don't like it get your money back.
Also we did a big promo when these were released where the egt kits were included for free. I am certain you can find a dealer who still has these on the shelf with the promo and it would make the system a bargain!
Also our EGT kit is not an add on module you need to hide. We were able to make it so that you use a simple plug in connection on our brain and install the probe and you are done!