Git Random - Chrome extension to replace new tab with random github user
Gitstalk - Discover what your favorite GitHub users are up to
Code Climate for Google Chrome - Code quality and test coverage, directly in GitHub
Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
Devo - Devo delivers real-time operational & business value from analytics on streaming and historical data to operations.
Dyllo - A clean and simple way to view a Github user's information