Have you heard about Glitch? Or colab?

I may be late to the party here, but I've been going through an awesome class on EdX.org on ML and for some of the exercises, we use glitch.com, which I had never heard of before. But it's a playground kind of site where you can put together a prototype of a JavaScript app (and perhaps other tech stacks are supported, too, but I was just using JS) and it provides a live, hosted, and sharable preview.

Another tool I learned in the process was colab, which is similar, but is a full-blown hosted environment for Python projects.