HBO GO VR is the virtual reality feature that gives you all of HBO on Daydream-supported Android devices to watch your favorite shows and movies in a virtual reality experience.
It works like the other HBO apps, let you watch your favorite HBO series and shows, like Game of Thrones, Westworld, Veep, and more. But in addition, it is compatible with any VR content that they would release. You just have to run the app, and wear your Cardboard glasses.
Note: You need an HBO subscription in order to have access to their content.