Unfortunately, most of what you’ll see on the HBO GO VR app, available on the Google Play Store to be used on the Daydream VR platform, is not 360-degree content.
Yes, if you use HBO GO, you can get HBO GO VR. If you don’t have HBO GO, you can download the app and get a month to try it out for free. You’ll be able to view rectangular content like Game of Thrones, Westworld, Last Week Tonight with John Oliver.
The big deal about this being an “unreleased” app is that it’s basically a beta test — expect bugs to hang around.