I don't have any issue using it on the iPad and iPhone, the functionality and UI is the same as on the Apple TV. It's a lot better UI then others multiview apps out there so far. This is my go to multview app for now until others come out with a better solution.
I just picked up 2 more CableCARDs from Comcast now I have total of 6 CableCARDs and that's 18 streams at once.
I'm not looking forward to it, if it multiview for sport contents only and they better not port stage manager to Apple TV and call it multiview.