Tv apps is a built in feature in directv, unfortunately it does not work in 90% of the places I have been watching directv. Usually you get a error 301, or, tv apps is still initializing try again later. This is how to fix it, at least on a belkin router. (Note... For some reason this only works for one tv.)
Step 1: Restart Your Receiver
First, Press MENU on your remote use the arrow keys to navigate to Settings and Help. go to... Settings, Reset, Restart receiver. And then do that.