This website (SiteSeeing.io) is just a very quick simple way for people to share their single-file HTML webpages with friends; there's no sign up, just upload your file and you get a private link. Or, you can share it publicly.
In addition, there is an "Explore" section of the website where you can view what other people have created (if they opted to make their site public). To begin with I've populated the "Explore" page myself with some simple pages so that people get the idea and have something to look at, but hopefully people will upload their own.
If people have any interest in this idea I could make two quick improvements: 1. Allow people to use a prompt to create their own webpage directly on the website. 2. Allow the upload of multiple files rather than a single html file.
I just wanted to see if other people have the same problem and if this could be useful. As always, I'm happy to hear what people think!