HDMI phone adapter

I have a 2nd home. Comcast is not offered in this area. I have Comast at my primary home and I have the Xfinity Stream app on my Smart phone. Of course, I can watch TV on my phone, but I would rather watch it on my TV screen. I am told that an adapter to view my Xfinity app from my phone to my TV will not work. Is there other options? This makes no sense to me. In addition, I dont want to use an HDMI and laptop. The phone is much more convenient.