Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Power Planner - Record homework and class schedule.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Sectograph - Sectograph app enables you to create a visual event tracker to keep track of all your upcoming events and due tasks right from the home screen.
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
Cozi - Cozi | Must-have app for the modern family