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.
Time Buddy - Time Buddy brings a colorful world clock.
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.
Time Zones Converter - Time Zones Converter is an application which as the name implies, is used for converting time zones.
Clockify - Simple and free time tracker. Perfect for small and mid-sized businesses as well as freelancers. Unlimited projects and users, unlimited productivity. Get all the premium functionalities, completely free.
World Clock - World Clock is an app that lets you see the time of any city in the world.