Motion Firefox - All-in-one time management tool in Firefox
Meekan - Connecting the world's calendars
Task Muncher - Task Muncher is a cross-platform and web-based application that is designed to organize and keep the track of everything and focus on munching the weekly tasks.
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
TideTask - Control your procrastination and never miss a task again
Sidequest for Slack - Create and track personal or support team tasks, 100% inside Slack.