Design Principles - An open source repository of design principles and methods
Random User-Agent - Automatically change the user agent after specified period of time to a randomly selected one, thus...
Facebook Design Resources - A collection of free resources made by designers at Facebook
User-Agent Switcher and Manager - spoofs browser's User-Agent string.
Facebook - Connect with friends, family and other people you know. Share photos and videos, send messages and get updates.
30 Seconds of Knowledge - Become a better developer, in every new tab.