Save-Point

I just stumbled onto this on Reddit: http://twinery.org/
It's a tool to write stories, normal ones or non-linear "choose your own adventure" style. It could be a handy tool for writing dialogue paths, branching story-lines for games etc., give it a try.

I did a quick test to see what you can do with it:
https://dl.dropboxusercontent.com/u/2802...0Test.html

Very similar:
http://textadventures.co.uk/quest/

I've got this awesome app called owning a pencil and paper. too bad it's analogue. :p