The free version lets you create and manage your tasks in a basic structured list format and filter according to priority. The Premium subscription offers synchronisation and access to project templates and more functional flexibility.
https://todoist.com/overview
An app that allows you to create and manage task lists in a format that you find easy to relate to. It also sync’s across all your devices, providing instant access to your current and future workload.
http://www.notion.so
This is a to-do list app that connects to your emails and social media to help you stay on track with reminders.
https://www.rememberthemilk.com
This will help you to organise your time, have different colour calendars for different subjects.
https://www.google.com/calendar/about
A basic list app that allows you to display your tasks in a structured list format according to each project.
https://tasksboard.app