HubPress - A free, open source tool you can use to build a blog using GitHub Pages and AsciiDoc. HubPress is a web application that makes it easy for you to maintain a blog.
SyntaxDB - Easily look up programming syntax for multiple languages
GitHub Personal Website Generator - Generate a personal website based on GitHub contributions
GitHub Visualizer - Enter user/repo and see the project visually
Jekyll-post-via-web - Update your GitHub-hosted Jekyll blog from your browser
Gource - Gource is a software version control visualization tool.