Gone - An ephemeral to-do list
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.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Pocket Lists - World’s Friendliest To-Do List App
Check - Check is a unit testing framework for C, which runs on environments such as GNU/Linux, GNU/Hurd, BSD, and Mac OSX.
Notesnook - Notesnook is a simple and private note taking app that keeps your notes organized and synced on your phone, tablet and computer.