I have an unlimited data plan through Verizon and I want to see if I can use it as an internet connection for my Microsoft Surface tablet. I know that if I want to use the mobile hotspot, I have to purchase a separate data plan for that. But I remember reading somewhere that Verizon allows tethering, which would allow the iphone to be used as a modem if connected via usb or Bluetooth for no additional cost. I don't see an option for this in the settings. Do I have to download an app or something?