One of my first hurdles with Gear VR was trying to cast my (Pop! OS) laptop screen to my Gear. There are some low latency solutions using a proprietary Nvidia app or Moonlight, but as the S7 in my Gear VR isn’t capable of running non-VR apps in VR, that was a no go.
The solution is very simple. As long as your computer and Gear VR phone are on the same network (also works if your laptop is on your phone’s hotspot or vice versa), you can use the FOSS software Deskreen on your computer (Mac, Windows, Linux) to stream your screen to other network devices.
After installing Deskreen, simply open the Oculus Browser on your phone (for me on my S7 it doesn’t work with Samsung Internet) and navigate to the URL given to you by Deskreen. After then accepting the connection on your PC, you can fullscreen the stream on your Gear VR.
Done! Now you have a reasonably low-latency stream of your computer in your Gear VR.