SlimPlanner - Team scheduling, resource planning, task management
Zulip - Chat for distributed teams. Zulip combines the immediacy of real-time chat with an email threading model. With Zulip, you can catch up on important conversations while ignoring irrelevant ones.
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.
Slack - A messaging app for teams who see through the Earth!
WorkPatterns - The modern manager's toolkit: 1:1s, feedback, & recognition
Flow - Stop managing projects from your inbox.