Flux - Application Architecture for Building User Interfaces
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Todoist 10 for iOS - A completely new Todoist for iOS
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.