This looks clever. I've seen PPT to web tools before (https://sparkslides.com/publish/, https://slidehtml5.com/), but I think the slide synchronization idea is new. I can't evaluate more than that as I don't use these.

In the past I have liked marp (https://marp.app/) for technical slides as you write in markdown, can use version control, etc. Powerpoint always felt odd as a developer.

To share public slides I've published to GitHub pages (https://github.com/robalexdev/marp-to-pages). I've seen professors use it for all their slides. But that doesn't synchronize slides, last I checked.

Reveal.js with the multiplex plugin [0] does that. I write my presentation in Quarto [1] and render them to reveal.

0: https://revealjs.com/multiplex/

1: https://quarto.org/docs/presentations/revealjs/