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.

ShiftJuggler - Shift planning, Time tracking and Holiday management for a group of people

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

Hubstaff - Simple yet powerful employee work tracker with screenshots, timesheets, billing, in-depth reports, and more. Understand productivity issues and act on them.

Cattr - Cattr is a free open-source self-hosted time tracker with desktop clients for windows, mac, linux.

TimeCamp - Simple and robust time tracking app to help you stay on the same page with your team while working from home.