Hey, I'm Lluis Vinent, co-founder of the Z-Anatomy association and creator of the Z-Anatomy app.
Indeed, the page is down due to the dissolution of the association, but the project is not abandoned, just inactive.
If someone wants to collaborate on its development, there is the GitHub repository where anyone can collaborate.
https://github.com/LluisV/Z-Anatomy
I'm currently working on a VR version of Z-Anatomy. Maybe in the future I'll open a new website. This project deserves visibility.