This is the sample application for Ruby on Rails Tutorial: Learn Rails by Example by Michael Hartl.

I am using RubyMine instead of Sublime Text 2 as my editor/IDE. Check out tips on using RubyMine in this project's wiki

For editing Markdown there are a number of options. Just go to Mac App Store and search for markdown. Mou is not at the MAS but is availiable and is free. I personally like a combination of Multimarkdown Composer and Marked and both are available from the MAS. Marked is just a previewer and works with any editor, plus it has a GitHub style for previewing. Multimarkdown Composer handles both Markdown and Multimarkdown syntax. GitHub's syntax is in between but closer to [Multimarkdown]. There is even a Markdown plugin for RubyMine which I am using for editing this README.md file.