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

Synology Note Station - Without needing to spend money on Evernote, Synology Note Station provides a desktop client to organize all your random notes in one place.

Microsoft To-Do - Task management tool

UpNote - A beautiful and clean cross-platform app for notes organizer

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

Note Board - Productivity app. Save information like a sticky notes.