Strangely, there is no YouTube app yet for the Samsung Gear VR. However, you can still watch YouTube 360 videos with the Gear VR using the Samsung Internet Browser.
1. Install the Samsung Internet browser app from the Oculus store.
2. Using the Samsung Internet browser, go to youtube.com.
3. Search for the 360 video you want to see.
4. When the video loads, look at the bottom of the video to see if you can change the settings (looks like a gear). If you can change the settings, change it to the highest available resolution. If the setting doesn’t show up, sometimes you just have to wait a bit for the resolution to improve.
5. Click on the bottom right of the video, then click on the square to maximize the view.
6. When the view is maximized, look at the top of the video, on the left side, where it says “More”. Click on that and choose the type of viewing (360 2D or 360 3D top-bottom are the most common ones for 360).
You can also use the Gear VR to watch 3D videos on YouTube. Follow the same steps, then when you see the viewing options under “More,” choose 3D side-by-side (the more common 3D format) or 3D top-bottom.
Another way to watch popular YouTube videos is to use the Vring In app, which has many of the popular 360 videos on YouTube.