Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
7 Sticky Notes - Welcome to the 7 Sticky Notes Website! 7 Sticky Notes is a cool 100% free desktop notes software that creates Sticky Notes directly at the Desktop of your computer to help you organizing your everyday tasks and to-do lists.
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.
Stickies - Stickies is a PC utility written to replace Post-It-style notes left stuck to your monitor.
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
Microsoft Sticky Notes - A brand new Sticky Notes for Windows has arrived!