Gone - An ephemeral to-do list
Simpli - Keep track of email, calendars, notes and more in a unified interface.
Streaks - The to-do list that helps you form good habits.
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Taskade - Make lists, organize your thoughts, and be inspired to get things done. Taskade is a collaborative space for your tasks.