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.

Timeglass - Multi-step & spoken timers for your workouts & cooking.

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

Workout Timer - A simple, customizable workout timer

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

WorkoutSesh - Free workout routines with interval timer