Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
Your Growth Hacks Aren't Working - Free new book by Steli Efti on B2B customer acquisition
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.
GrowthHackList - 100+ curated growth hacks for makers + early stage startups
Primer - CSS toolkit and guidelines that power GitHub
Hacking Marketing - Agile practices for smart marketing