Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Prodeus - Track your time learning on YouTube to earn your free degree
Any.DO - The #1 task management app used by over 11 million people globally, Any.do is your free mobile and online task manager for Android, iPhone, Web and more.
Annotate.tv - Optimize your learning on YouTube
Microsoft To-Do - Task management tool
Sidenote - Timestamped notes on YouTube videos