30 Seconds of Knowledge - Become a better developer, in every new tab.
Random User-Agent - Automatically change the user agent after specified period of time to a randomly selected one, thus...
know/how Product Managers - A weekly newsletter with 5 practical tweet-length PM tips
User-Agent Switcher and Manager - spoofs browser's User-Agent string.
Tampermonkey - Greasemonkey compatible script manager.
Calligraphy - Custom fonts for Android