Gitstalk - Discover what your favorite GitHub users are up to

CodeKeep - Codekeep lets you store and share bits of code and text with other users. Snippets can be organized into folders/labels for instant reuse.

Refined GitHub - Browser extension that makes GitHub cleaner & more powerful

CodeMyUI - Handpicked code snippets you can use in your web projects

Anyfiddle - Build, run and share code in any language from your browser

Dyllo - A clean and simple way to view a Github user's information