Taskful - Deadlines, meet your match.
Gone - An ephemeral to-do list
Calendarist - Time blocking companion for Google Calendar
Simpli - Keep track of email, calendars, notes and more in a unified interface.
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.
Centered - Centered helps you get into a Flow State faster and stay there longer so you can do your best work.