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.
Twilio - Brings voice and messaging to your web and mobile applications.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.
CallHippo - Easy to use Phone System with World-Class Support