Microsoft To Do is a free, cleanly designed task manager built on the bones of Wunderlist — which Microsoft acquired and rebuilt from scratch, launching in 2020. Deeply integrated with Microsoft 365, it syncs tasks from Outlook, Teams, and Planner, making it the natural task layer for anyone in the Microsoft ecosystem. Its My Day feature encourages intentional daily planning each morning, while Smart Suggestions surface overdue and upcoming items automatically. For Microsoft 365 users, it is the most frictionless task management option available at zero extra cost.

Reference:

Microsoft To Do on Wikipedia

https://en.wikipedia.org/wiki/Microsoft_To_Do