I just shot a ton of 3D Spatial video on my iphone 15 promax. And I watched the video on my iphone in 3D without anything more than an app where you convert the video clip to 3D SBS full resolution with a special clip on viewer.
The app is in the Apple app store "Spatialify"
Then use this clip on viewer:
I have a couple of these that came with my 3D camera. I use them when traveling as oppose to viewing with my Oculus Quest. Now with Apple making 3D available in the iphone and these viewer lenses, I don't need to bring the Meta Quest3 with me, or a special 3D camera.
It is important to calibrate the Side by Side 3D to your eyes IPD in the app otherwise you will see a double image. You home the lenses close to your eyes like binoculars.
The Spatialify app converts the Apple Spatial Video on the iphone very fast. I shot a 55 minute Spatial video 9GB file size and it did the SBS conversion with HDR in under 10 minutes.
There are other apps to do the conversion too and I tried a couple but settled on this one since it worked so well, was fast, and couldn't find any bugs.
Note- if you wish to save the Spatial 3D video for general general external viewing, the Apple Vision Pro and Meta Quest 3 now will allow you to transfer the origonal video from the iphone to these and they will play without the SbS conversion. For all other displays and You Tube 3D you will need to convert to standard SbS or Top Bottom format. YT does not convert Apple Spatial 3D format (yet).
3D is amazing upgrade from 2D, IMO. Fascinating that Apple has made 3D popular again. If you want an easier way to view Spatial videos, the probably the Meta Quest 3 is a good all round choice for much lower price that the Apple Vision Pro.