Spacedoo - Short actionable marketing hacks
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
DeskAlerts - Send alerts to any corporate device: PCs, phones, tablets, etc.
Primer - CSS toolkit and guidelines that power GitHub
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.