Google's Tasks is a simple and clean to-do manager designed to help you stay on top of your tasks and projects, wherever you work.
Create tasks and subtasks: In the app, you can tap the "Add a new task button" to create a task. You can set a due date -- or leave it blank, if you want a daily reminder -- and write yourself a note in the "Add details" field. You can sort by date or arrange your list in your own order.
Integrates with Gmail and Calendar: In addition to using the app, you can create tasks in Gmail. Tap the Tasks button over on the right side of Gmail, to manage tasks. You can drag an email over to the Tasks side panel to create an item to track. To manage your tasks in Calendar, in the My calendars section on the left, click Tasks.
If you had previously kept track of items with the older version of Tasks that was part of Gmail, those tasks appear in a separate list you can access from either the hamburger menu in the app or from the Tasks side panel in Gmail.
Works across devices and platforms: In addition to Android, Tasks is available on iPhones and in Gmail and Google Calendar.
Overlap but no integration with Google Keep and Reminders: While Tasks overlaps with some of the features of Google Keep and Reminders, it lacks the breadth of either of those tools and doesn't integrate with either one.
Lacks features found in other to-do apps: Tasks lacks basic features found in other to-do apps, such as the ability to add attachments and you can't set a repeating task or set a due date for an hour from now. It also lacks a home screen widget.
A simple task manager, Google's Tasks app lets you manage to-do items from your phone, Gmail, or Google Calendar. If you are looking for anything beyond simple task management, however, you'll need to look to Todoist, for example.