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

Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.

AprilZero - A personal dashboard with a lot of metrics and an amazing UI

EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.

Sherbit - Sherbit lets you visualize stats on your life based on the services, devices and apps you use.

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