Planner

Microsoft Planner is tasks-and-project hub that allows you to track and assign work across a team. Create a new plan, assign it to an existing team or creating a new team for a project, and you can populate the plan with tasks. Group tasks into buckets, set due dates, create sub tasks, assign tasks to team members, check-off completed tasks, and view analytics on team progress. 

Planner integrates with other apps in the Office 365 suite for ease-of-use. For instance, you can integrate Planner with Outlook to put due dates for tasks on your calendar. Or, you can integrate Planner with Teams so you can check tasks, project progress, and chat with team members all within the same window.  

Scroll down for few Planner video tutorials, or visit Microsoft's Planner learning center.