It is a software design to view panoramic photos (for example generated by Hugin). It is based on Photo Sphere Viewer, a web viewer (for lack of anything better). As a result, it is quite resource-intensive, especially on large images.
It's just a little app that launches a web page with Photo Sphere Viewer inside, which is enough for my use. There will probably be no improvement on my part except for updates of the libraries used.
It allows you to read panorama photos of type equirectangular. It is not necessary for the image to be 360° complete.
The software is also available under AUR.
The source code is available on my git repository under MIT license.