Cool! I've been actually thinking I should get something like this for Sublime because I'm often correcting silly mistakes in my Github repo readme's that I only notice once the Markdown renders in browser.

Only minor comment is that you say "realtime" but from the demo it seems like that the view is updated only when you hit save right?

Off to test it out now!

Edit: went through all the steps and live preview doesn't seem to be working. Does the plugin work under ST3? I also assume that there's a missing step in the readme, so I cloned the git repo to the Packages sub-directory as "Livedown". Hoping I've just made a silly mistake with the setup.

Edit #2: So I verified that running from the command line works and it loads my markdown file without any problems. The link with Sublime doesn't seem to be working though, so when I make changes, I can see them in the browser window by refreshing. Guessing something is screwed up in the way the plugin is setup on my laptop.