GrowthList - A crowd-sourced list of growth hacks
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Q by SubStrata - Q is your email communication genius for B2B sales.
HelpDocs - Educate your users with a super simple knowledge base that’s built for teams just like yours.
Email Marketing: A Beginner's Guide - Master email marketing with these 3 short ebooks from Drip.
phpMyFAQ - phpMyFAQ is a world’s most popular mobile-friendly, feature-rich and open-sources FAQ software that uses PHP 5.