The Memair app directory is closed for now. This repo serves one page at apps.memair.com that says so and links to the developer docs.
Apps can still connect to Memair through OAuth and the GraphQL API. The docs explain how.
The apps.memair.com DNS record points at GitHub Pages. While this repo publishes a site with that CNAME, the subdomain shows a page Memair owns. A DNS record that points at GitHub Pages with no site behind it is open to a domain takeover (GitHub Docs, "Securing your custom domain"). To retire the subdomain, remove the DNS record first.
The listings, the gallery layout and its assets are in the git history. Commit ade2a81 is the last one with the directory in place.