Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.

Wunderlistux - An electron wrapper for wunderlist made with love for Linux (specially for elementary OS)

Todoist - Todoist is a to-do list that helps you get organized, at work and in life.

OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.

Mirakel - An easy to use and lightweight To-Do App.

Remember The Milk - Remember The Milk is a task and time management application for mobile devices.