Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
GrowthList - A crowd-sourced list of growth hacks
Fibery - Work management platform that adapts to companies and grows with them.
GrowthHackers Projects - Growth collaboration software for teams 📈
Producter - Product management tool for product-led teams
Marketing Examples - A gallery of real world marketing case studies. Updated every day.