I recently added the Vegatouch Mira module described above, which is the BlueTooth module (~$550). I did not like the idea of having to pay $300 more, plus a monthly fee for their "Eclipse" WiFi version.
The install literally took 2 minutes. You access any one of the existing FireFly connections, the easiest for me was the one in the overhead driver's side locker. Then you unplug the orange cable from the FireFly touchpad and plug that cable into a splitter along with two other supplied cables. One of the new cables goes to the Mira module and the second one goes back into the touchpad. I then tucked the module into the locker behind the touchpad screen.
The Vegatouch app gives you all the functionality on the phone as you have on the screen. Itís definitely not necessary, but it's nice to have if, for example, you're cruising down the road and forgot to turn off the water heater, or you're sitting outside under the awning and want to turn on the exterior lights.