Agenda - A date-focused note taking app for both planning and documenting your projects.
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.
Notepin - Extremely simple note-taking + blogging ✍️
Slack - A messaging app for teams who see through the Earth!
Bear - Bear.app is a note-taking and content writing app that helps you boost productivity with its intuitive tools.
GrowthList - A crowd-sourced list of growth hacks