Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
Laverna - Laverna is a JavaScript note taking application with Markdown editor and encryption support.
Notepad Checklist - A checklist made by notepad.pw, easy short and fun to use.
Notezilla - Colorful & powerful sticky notes app for Windows & Phones.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Simplenote - The simplest way to keep notes. Light, clean, and free. Simplenote is now available for iOS, Android, Mac, and the web.