Code Verify: An open source browser extension to verify code authenticity on www

Meta has made an extension that verifies the hash of the web version of messenger and whatsapp and it's using Cloudflare as a trusted 3rd party. Cloudflare's writeup is at https://blog.cloudflare.com/cloudflare-verifies-code-whatsap...

This seems like a good step in the right direction, but I am trying to figure out if anyone else can use this to publish more secure web apps and I can't seem to find any instructions or mentions of how this is usable for anyone else than just meta and their users. Is it?