From a Plex email this morning:
Xbox One and PlayStation apps are now FREE for everyone!
Xbox One and PlayStation users, have we got a great gift for you! Plex apps for your favorite game consoles—all of them—have graduated from their preview periods and are now free for everyone! Joining Xbox 360, as well as our other big screen apps, these newly free ones give users all the basic functionality at no cost. For those of you with a Plex Pass, our premium features, like Parental Controls, Vevo music videos, and Trailers & Extras, look awesome on the big screen.
Woohoo! My PS4 has now become the one box that does it all. Plex just saved me buying a new Apple TV.