Random User-Agent - Automatically change the user agent after specified period of time to a randomly selected one, thus...
Product Manager Handbook - Interviews w/ product managers + weekly newsletter
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
User-Agent Switcher and Manager - spoofs browser's User-Agent string.
Everything.PM - 300+ resources & tools for PMs, sorted by votes