Kudos to your daughter for self-teaching German!
She might have a look at
https://anton.app/de/
This App covers all major school topics, from class 1 to 10... and it is free.
I am using markdeck with vim. Markdeck has an auto-reload, that means, every time you save your markdown or change something in your assets-folder, the web view gets reloaded automatically; so not really live preview, but auto-reload on save...
And markdeck has a standalone-exporter: it generates a single html file with all resources embedded (url-data, base64, ...); one file to send/open/view, but with working animations and the like (even the terminal session works)
In fact, there already is such a (okay, rather short) section in the README [0].
But I plan to incorporate the other tools mentioned here.
Only the feature comparison table with all of these tools against all of the features mentioned here will have to wait, I am afraid...
I had to use gitpitch for one presentation only, so correct me if I am wrong, but with gitpitch you cannot see the resulting slides before you push them to the repo, right?
We had more than 200 commits at the end of one day, 150 of them to solve minor layout problems... with a (feeled) round-trip-time of 10-20seconds, that became frustrating quite fast...
It does not _require_ a VCS, but you can bring/use your own quite easily. Why? because most of the slide sources are in text format, so working with them under version control is easy compared to the big binary blobs known from powerpoint/pages/...
It is based on another tool I have written, a2sketch[0]:
that uses asciitosvg (still the php-variant[1]), generates a svg and feeds that into rough.js[2] (converts svg in sketchy svg)
A sync to S3 is a nice idea. And it is completely independent from the generator you use... so I would see that functionality as a utility command, called when everything else is finished.
btw: with markdeck, I tried the completely different approach: do not dependent on an uplink, neither when authoring, nor when presenting...
I use a simple presenter with simple forward/backward keys...
DeckRocket looks cool, but unfortunately I cannot build it on my machine (to convert the app from swift 2.4 to swift 3 or even higher, xcode8 or so is needed... and that is not a priority at the moment)