The Armytrix exhausts come with a OBDII dongle that plugs into your OBDII port. This is how the conventional remote works for your exhaust to change from quiet to race mode. With this dongle, it has bluetooth built in so now it works with the new iPhone app. Since the dongle is plugged into the OBDII port, it also works as a diagnostic and datalogging tool. The app lets you check various sensors that the car reads such as RPM, Speed, Battery Voltage, EGT, Oil Pressure, Oil Temp, Water Temp, AFR, and much more. You can select these 2 at a time and view them like digital gauges. We also give you the ability to datalog these values which it saves a a TXT file to be emailed and evalutated later.