[pythonaut_16]

Here's another pretty cool one using Elixir and Phoenix Channels (Websockets): https://github.com/ernie/venture

It also has markdown based slides but syncs the presentation to clients via websockets, and allows for interactive slides with things like Polls and live chats.

[davidbanham]

Reveal.js can also sync the presentation to clients via websockets with its multiplex plugin.

You can use the same mechanism to have the presentation on a computer connected to your projector and control the slides from your phone (or any other computer)