30 Seconds of Knowledge - Become a better developer, in every new tab.
PM Starter Pack - Practical guide on how to get started in product management
Random User-Agent - Automatically change the user agent after specified period of time to a randomly selected one, thus...
Learn by AngelList - Venture Education Center by AngelList
User-Agent Switcher and Manager - spoofs browser's User-Agent string.
Sidewise - Source the best engineers, without understanding code.