Facebook has been slowly increasing focus on sharing video, most notably with Facebook Live. Like Google Plus/YouTube, Facebook supports uploading 360-degree photos and video. If you have a Gear VR, you can now use Facebook's 'Facebook 360' application for viewing immersive content on the go.
You can probably guess from the name that Facebook 360 does exactly one thing - play 360-degree content from Facebook on the Gear VR. The app currently has four feeds - an 'Explore' view with recommended content, a list of 360-degree content from your friends, saved videos/photos, and a timeline of your own media.
The user interface is quite nice though, and you can even save or share content without leaving the app. Facebook says it hopes to bring the app to "more platforms over time," but for now, you can only get it on Gear VR-compatible Samsung phones.