The internet is a limitlessly weird place, which is kind of the reason why we love it. But when the weird includes a little bit of filmmaking and NERF nostalgia—well—we get this. Filmmaking YouTubers (YouTubing filmmakers?) Sam and Niko not only mounted a GoPro HERO Session to an arrow and shot it at their buddies, but they also added stabilization in post to create this awesome, spinning, "arrowcam" video. Check it out below!
Now, if this was a video that simply showcased footage captured by a "GoPro arrow " it'd be pretty cool—I mean, how else are you going to get that smooth spiral camera motion? (I'm sure there are other ways.) However, Sam and Niko headed into post and manually rotated the video the opposite way in which the arrow was spinning in order to make the world steady while the edges of the frame rotated. (Essentially the exact opposite of what the source video does.)
If you're interested in doing your own "arrowcam" footage, you just need to get your hands on an action cam (a HERO Sessions are good because it's small, light, and a square) and some arrows with a soft tip—LARPing arrows might work well. Measure and cut to the dimensions of whichever camera you're using, tape it up, and then go to town. The post work might take some doing, though, but I imagine you could pull it off by simply setting accurate keyframes that will rotate your image in the opposite direction and at the same speed as the arrow is rotating.
Source: Sam and Niko