Google Calendar - Spend less time managing your day & more time enjoying it
Streaks - The to-do list that helps you form good habits.
Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
Taskful - Deadlines, meet your match.
Business Calendar - Powerful and easy to use calendar app for Android including weather, widgets and tasks.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.