Sit Still for iPhone.
Something wrong, or an idea? Email sitstillapp@gmail.com. Settings → About → Send feedback opens the same address with your version, build, iOS version and device model already filled in, which makes anything reproducible much faster to fix. Expect a reply within a few days.
Sound has to be on for a session to keep running in the background. With room sound switched off, iOS suspends the app, and a countdown will not finish or chime until you open it again. Settings → The room has the switch.
It shouldn't — room sound is mixed under whatever else is playing rather than interrupting it, and it ignores the ring/silent switch. If it is louder than you want it under music, Settings → The room has a volume slider and a Listen button.
Check Settings → Focus shield: Companionship is the default and blocks nothing. Whitelist and Strict both need Screen Time access, which iOS asks for the first time you pick one. Screen Time cannot shield some system apps, and it quietly stops working past 50 chosen apps or websites.
Open Sit Still. A shield is a system setting rather than something the app holds open, so it survives a force-quit — and opening the app clears any shield with no session behind it. If you have deleted the app while a shield was up, reinstall it, open it once, and the shield comes down.
iOS refuses to monitor a window shorter than 15 minutes, and the start and end callbacks only arrive while the device is in use — a phone face-down at 22:30 gets its lock when it is next picked up.
The reminder wins on any conflict. Scope is Sit Still's own Reminders list plus reminders you deliberately linked; a reminder added to another list is not picked up. Deleting travels both ways — deleting a task deletes its reminder, and vice versa.
Leaving takes a deliberate 1.3-second hold precisely so it doesn't happen by accident, and time left that way is not banked. Finishing early is different: an open-ended session, or a countdown paused past the first minute, banks what you did sit through.
Two per minute of a completed session, with a bonus past half an hour, and roughly a one-in-four chance that an accessory you don't own turns up instead. They buy the two seasonal rooms of the month and things for the cat to wear. Every permanent room and every cat is free.
Seasonal rooms rotate at the end of the month. One bought with whiskers stays yours; the ones you didn't buy are replaced by the next two.
Settings → The room → Save room as wallpaper needs permission to add to Photos, which iOS asks for once. If it was declined, turn it back on in the iPhone's Settings → Privacy & Security → Photos. The app can add images and cannot read your library.
Delete the app. Everything Sit Still knows lives on the device and goes with it — there is no account and no copy anywhere else.