FinancialForce PSA - FinancialForce.com provides cloud back-office applications for Salesforce CRM.
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.
Projector PSA - BigTime Software Acquired Projector to Become The Leading Operating Platform for Professional Services!
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
VOGSY - Professional service automation tool built on Google G Suite
Hubstaff - Simple yet powerful employee work tracker with screenshots, timesheets, billing, in-depth reports, and more. Understand productivity issues and act on them.