I have a FM Radio app. If I listen to the radio does it use data on my verizon account, or is it just "over the air" like a standard FM radio?
It IS a standard FM radio receiver that is built into the D3's chipset. I believe it is part of the bluetooth/wifi module. The only thing the app does is provide an interface to the tuner. It has nothing to do with the cellular network, hence the fact that you have to plug in headphones to use it. The headphone wire acts as an FM antenna.