Google has expanded its popular Calendar app to accept to-do entries to help those of us who lose track of all our tasks. The main difference from Reminders, which was previously available and continues, is that the tasks will remain active and stay atop the reminders list until finished - or until they are deleted by being swiped away.
The new function is part of an update of the Calendar app on mobile devices. Google says it also working on incorporating the to-dos into their web calendar.