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.

usageDirect - Android app to read out usage statistics from system

ActivityWatch - Log what you do on your computer. Simple (yet powerful), extensible, no third parties.

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

Sysinternals Desktops - Desktops allows you to organize your applications on up to four virtual desktops.

LeechBlock - LeechBlock is an extension for Firefox and Chrome that allows users to block time-wasting sites.