Why a fine jar instead of a notification
Every other screen-time tool is a notification or a friction. Apple Screen Time taps you on the shoulder. One Sec asks you to breathe. Opal closes the app for the duration of a focus session. None of them cost you anything when you ignore them. Loss aversion. The behavioural-economics finding that humans treat losses as roughly twice as motivating as equivalent gains. Only kicks in when the loss is real. The fine jar is the smallest possible mechanism that creates a real, dated loss.
How the math works
The math is the same on every device, every day. Your limit is whatever you set it to (a typical first-week limit is 90 minutes). The moment your total foreground screen time crosses that limit, a 15-minute clock starts. Every 15 minutes that the clock ticks while you are over, a lock event fires and target apps in your block list become unusable until you complete the redemption action you chose at onboarding (25 pushups by default). There is no money cap because there is no money charge. The cost is exercise time, not dollars.
When the lock clears
Lock events stay in your jar until you clear them via the chosen redemption. Camera-counted pushups, HealthKit-verified steps, camera-counted squats, or 10 mindful minutes timed in-app. Phone, Messages, FaceTime, and Maps remain accessible regardless of lock state. Only apps you explicitly added to your block list during onboarding are affected.
Behavioural redemption. The 1-week grace window
Each new lock event is pending for 1 week. During that window you can clear it by hitting your chosen redemption target. 1,000 steps, any logged workout, 10 mindful minutes, 25 camera-counted pushups, 25 camera-counted squats, or an honor button. Unredeemed events stay in the lock count and the apps stay blocked until you act. This is the single biggest difference between ScreenFine and a pure punishment app: the lock is a prompt, and the prompt has an exit.
Pause anytime
You can pause the jar at any time from Settings. New lock events stop the moment you tap pause. Existing pending locks (within their 1-week redemption window) still resolve. If you clear them, the apps unlock; if you do not, they expire silently while paused. The $1 weekly subscription continues until you cancel it; pausing the jar keeps your streak alive but stops the lock mechanism. Pausing is a feature, not a workaround. Some weeks you genuinely need a break, and the right move is to stop the mechanism rather than ignore it.