It is synchronizing your existing tasks, events or appointments from Google or Microsoft calendars. You can also add them manually. If you have more than one task a day, the circle grows with different colors. More tasks, more color, less free time. It is a colored image of your day... Reminders, images or files adding are included. I started using it yesterday and I'm really satisfied:) Thanks for the comment @mawahab, I wish you a great day:)