StayFocusd

StayFocusd is a site budget, and it has been one for a very long time. You give yourself an allowance of minutes per day across a list of sites you already know are trouble; once it is spent, those sites stay dark until the next reset. Alongside the allowance there are scheduled time periods when blocking is absolute, a domain list you maintain yourself, and the Nuclear Option, which locks the setting so you cannot bargain with yourself in the middle of an afternoon. It is free, it runs in Chrome, Firefox and Edge, and it is good at exactly one thing: putting a measurable price on the fourth visit.

Compared with LeechBlock or Cold Turkey the difference is the unit. Those think in schedules and sessions; StayFocusd thinks in minutes, which is the right shape if your problem is quantity rather than timing, and useless if you can simply work around the clock. The obvious hole is that it only sees the browser it runs in — a second profile, or a phone, defeats it — and it never asks why you opened the tab. Before relying on it, check which browsers it actually covers rather than assuming yours is one of them, set the allowance somewhere honest because zero just moves the fight into the settings page, and read the permissions: any site blocker has to see the addresses you type, which is the real price of a free tool. Expect thin reporting, and a budget that applies per browser install rather than per person.