A developer by the name of Jimmy Zhang appears to be the first to get an app on the Vision Pro App Store that allows you to view your own spherical pano's. It's called "A 360 Viewer." So far it's a simple implementation but works great. Loads images from Photos but also has a file browser so you can load them directly from the Files section on VP. As Apple appears to have a pixel limit of just over 16,000 wide, he put resizing into the code so you can load files that are larger and they will be downsized accordingly. Cool that we can now see our own 360's in an immersive environment!