We have been working on a little Mac app called Keynote Extractor. It helps you get better HTML exports out of Keynote presentations.
We did this first and foremost to scratch our own itch: I wanted to be able to show presentations like this one in a modern way.
We also used it as an experiment to try out shipping an app using Electron, and whether it was feasible to get the app on the Mac App Store. That last part is still an ongoing process.
We’re testing the application in beta before hopefully releasing it on the App Store soon. Interested in trying it? Shoot me an e-mail at firstname.lastname@example.org.