Web Timer is described as 'Keep track of how you spend your time on the web. Web Timer keeps track of the tab that you are actively using and updates its stats every 3 seconds' and is an app in the Office & Productivity category. There are three alternatives to Web Timer for a variety of platforms, including Windows, Chrome OS, Google Chrome, Linux and Mac. The best alternative is Webtime Tracker, which is free. Other great apps like Web Timer are TimeYourWeb (Freemium) and Website Time Tracker (Free).
TimeYourWeb is the most detailed time tracking Chrome Extension. It shows how much time you spent on any site on any day/week/month. It shows when you started watching any page and how much time you was on it. Is shows how your habits are changing.