I believe you'd need an HDHomerun and the app for the NP.
I don't believe there is any native app that just streams your TV feed, unless DTV offers one themselves.
I was wondering this too. In an ideal world I'd have a network enabled freeview box that my nexus player picked up and other devices could connect too as well, then an external hard drive on the tuner to record on? It would be lovely.
I side loaded the app a long time ago and the app loaded no problem but as others have said a mouse is required and I was never able to get any video content to load. It may be different now this was months ago. Would be nice if they would fully support it. Might harm their hardware business and leasing fees if they did though.
If you are in the UK you can use the TV Catchup app.
Kodi. Then install usatv now addon. Get six major network channels free. https://www.ustvnow.com sign up for free.
If direct tv offers a live streaming app for Android then you may be able to sideload and control with a mouse.