I would be shocked if ESPN was willing to allow non-subscribers to watch online content for free.
Or are you talking about all of the non-broadcast materials, like womens vball and tennis and stuff? If so. . . that would be fine. But, honestly, nobody will watch it. If you aren't willing to turn on the "BYUtv" app to watch that stuff live or re-play, how would a "BYUtv Sports" app make a difference?