Vacation Tracker - The easiest way to track your team’s vacations and days off.

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.

Punchtime - Nifty time tracking for Trello users and teams

Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.

Circlebatch - Circlebatch helps people working on side projects, open source, or startups find contributors to join them.

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