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.
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Power Planner - Record homework and class schedule.
Jira - The #1 software development tool used by agile teams. Jira Software is built for every member of your software team to plan, track, and release great software.
Dreamie Planner - Dreamie Planner app contains a built-in diary through which users can write important details about their daily tasks and can send the content of the diary to their friends and colleagues.