Clocker - Keep track of people in different time zones
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.
World Clock iOS 8 Widget - Check the time, anytime. Just pull down Notification Center.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Dato - Better menu bar clock with calendar and time zones
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.