Hello all and thank you for posting,
@mnollner - As mryflyguy stated, you don't have to have a cable box to view On Demand, you just need to have a cable card.
@mryflyguy - I replied to your other post asking to send me a private message, I'd be happy to help.
Looks like Comcast will end support for the Tivo/Xfinity Video On Demand app in Michigan next month. I received a message saying this when I turned on my TV this morning. I called Comcast and they confirmed. They said something along the lines of the app being based on "old technology" that can cause "a security issue". I asked whether I could get more detail and he said further detail is not available at this time. There is a streaming app for Roku and some Samsung TV's, but otherwise my understanding is that customers will be forced to rent X1 boxes from Comcast in order to continue to used Xfinity On Demand.
Additional details at the link below, thanks!