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 Sink - Time Sink helps you track how you spend your time on your Mac.

RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.

ChatterBlocker - ChatterBlocker is the prime software to reduce the nearby conversation’s distraction that allows you to focus on your work.

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.

Strict Workflow - Enforces the Pomodoro time management technique by blocking distracting sites