I seem to be having the same problem. It's like watching SD TV station on a wide screen HD (for comparison). I don't see any settings to take up the full screen. Is this because of the way NBC is streaming it? Asking because during the game on regular TV, Verizon commercial came on, demonstrating the NFL app, and they showed the app / video screen of what appeared to be a live game, taking up the entire screen on the X. It is however playing very well streaming through wi-fi. With my old Sprint service, you had to use their TV app with 3G only, and it looked like crap.