Such a site would allow you to use the web apps from within the site, see web app prompts, fork prompts, generate web apps on the site via AIs of your choice, etc.
You can try <a href="https://twitter.com" rel="nofollow">https://twitter.com</a>. Copy your amazing prompts, and people will copy-paste them and share them. The site may include some nazism but it's a side-effect that you can ignore.