Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
Do Things That Don't Scale - Discover new unscalable ways to grow your startup
TweetFavy - The Growth Hacking Tool for Twitter. Marketing automation software / Growth Hacking tool designed to grow your social media influence and attract real, targeted and engaged Twitter followers.
Fibery - Work management platform that adapts to companies and grows with them.
Primer - CSS toolkit and guidelines that power GitHub
GrowthList - A crowd-sourced list of growth hacks