Iphone can not do that via Bluetooth. Only Android can do that via Bluetooth. Iphone requires it to be done via WiFi which increases the price substantially as the WiFi OBD2 scanners are much more expensive than Bluetooth. The Iphone just simply will not transmit or receive data like that via Bluetooth.
DashCommand and Rev are two very popular apps, but again very expensive. I used DashCommand and was not impressed for a $50 dollar app. Rev apparently is better though, I just haven't used it.
There are several WiFi OBD2 scanners out there, but the best is the PLX Kiwi WiFi unit. Over $100 bucks for it, but that is pretty much what you are going to find with these types of scanners.
Unfortunately it's not as easy as a BT dongle and Torque app like Android
I use a laptop based OBD2 scanner and it is just that. A READER. Nothing that will cause any warranty issues. Period.