Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Flashnote - Flashnote is a quick notes manager
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.
Bundled - Bundled is a beautiful note generation application that allows users to create lists, reminders, and organization services by using instant syncing backup.
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.
Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.