This extension is really useful if you are interested in your browsing activity, which I think it is really handy for everyone. The extension tracks your website statistics and then it will provide them to you in good looking charts.
Time Stats collects Daily statistics, Monthly statistics, Time spend on sites, and Total amount of time, Most visited domains, domain zones (.com, .org …), the busiest days and some more.
You can categorize the sites into categories defined by you. And then you know how much you spend working, having fun, watching videos, shopping, etc.
Eg: I categorized my websites into Fun, Work, Persona, Fashion and some other pages and I can see that I spend 47% of my browsing time having fun and 39% working. You can take a look on the each category in more detail and see specific websites.