GrowthList - A crowd-sourced list of growth hacks
Decidr - Make better decisions with quick A/B polls
GrowthHackers Projects - Growth collaboration software for teams 📈
Go Fucking Do It - Set a deadline and a price. If you fail, you pay.
Marketing Examples - A gallery of real world marketing case studies. Updated every day.
AbTest.io - A free url shortener with A/B testing features