GitHub Visualizer - Enter user/repo and see the project visually
SyntaxDB - Easily look up programming syntax for multiple languages
Gource - Gource is a software version control visualization tool.
Learn X in Y minutes - LearnXinYminutes isn’t a good way to learn your first programming language, but it’s a great way to...
OctoSearch - Search the repositories starred by your following on GitHub
The GitHub Matrix Screensaver - Latest commits from GitHub visualized Matrix-style