Secure, End-to-End encrypted and journaled personal information (contacts and calendars) cloud synchronization for Android, the desktop and the web.

• per-user config option to enable this feature
• only available when tasks app is enabled
• tasks have a checkbox in front of them, clicking this checkbox will mark the task as done.
• clicking the task itself should take the user to the task app
  • when going back to the calendar: get back to the same time-range?