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.
Kanban Tool - Simple and effective online application for visual project management.
KanbanMail - A Kanban board for your emails.
Wekan - The open-source Trello-like kanban (built with Meteor)
Sunsama - Calendar and scheduling for teams
Ora - Welcome to your team’s command center. A place to track projects. Tasks. Time. Commits. Status Reports. Your entire product or business! It's the fastest-growing productivity suite your team needs right now!