Managing millions of tasks, Todoist is an online task management app and todo list. It has Web, iPhone, Android, Chrome, Firefox, Outlook flavors (and more!).

Google Tasks is a very simple task list. Works inside Gmail, Android, and Calendar seamlessly.

Any.do is a simple & powerful way to manage Projects, To-do lists & Reminders. Available on Web, iPhone, Android, Mac, Windows & More.

Microsoft To-Do is an intelligent task management app that makes it easy to plan and manage your day. With its intelligent Suggestions, To-Do removes all the clutter and empowers you to focus on what's important, when it's important.

Wunderlist is the easiest way to get stuff done. Whether you’re planning a holiday, sharing a shopping list with a partner or managing multiple work projects, Wunderlist is here to help you tick off all your personal and professional to-dos.

Things is an award-winning personal task manager for Mac and iOS that helps you achieve your goals.

OmniFocus is an incredible task management platform for Mac®, iPad®, and iPhone®.

TickTick is a simple and effective to-do list and task manager app with seamless cloud synchronization across all your devices.

Zenkit is a flexible workspace you can use to organize the things you care about, in the way that suits you best.

Remember The Milk is the smart to-do app for busy people.