Site Limiter от Kiran Adhikari

Version 1.0.0

Site Limiter limits the total time you spend on a website.
You can copy paste the url of the site that you want to limit your time on, and enter the time in seconds to limit that particular website time.
As of now, the time limit is a global limit, i.e. your limit does not renew each day or week or month.

Based on the my availability and usage of this extension, I'd add more features in the future.