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

Lifetick - Lifetick is an online Goal Setting application with a stylish, easy to use interface.

Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.

Beeminder - Beeminder

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

Habitica - Habitica is a free habit building and productivity application.