Gitstalk - Discover what your favorite GitHub users are up to
GitNews Web - Trending repositories from GitHub, HackerNews & Reddit
Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
CodeBottle - MIT-licensed reusable code snippets
xoscope - Xoscope uses the input of your Sound Card, EsounD and/or a ProbeScope/osziFOX and Bitscope-Hardware.
SyntaxDB - Easily look up programming syntax for multiple languages