I used the mobile app (NBC TDF All Access) last year and it worked great. you could watch live or on demand. It gives you a menu of all the completed stages to date, and you can choose whichever one you want to watch, whenever you want.

This year I bought the online package so I could watch on my bigger Mac screen and that's working well too. But to be honest, I forgot that could stream from my iPad to Apple TV and see it on an actual TV screen - I should've stuck with the app, it's much cheaper!