Create a family chart in the app, print it for the fridge, then update chores with taps or Siri as life happens. Kids keep using the page.
Kids use the page. Grown-ups use the app.
Teenagers can do the laundry start to finish, mow the front yard, cook a weeknight dinner, wash the car, babysit a younger sibling for an hour, clean their own bathroom. If your family pays for bigger jobs, keep those rules explicit; stars can still track the daily rhythm. The chart is an agreement more than a chore list at this point.
Six to ten, but each one is bigger. A teenager does not need twelve rows; they need three or four jobs that actually move the household forward. Mow, laundry, dinner, bathroom. The rest can stay informal.
Stars are a record, not a currency. Use them to see what happened during the week. If your family pays for bigger extra jobs, keep that rule separate from ordinary family responsibilities.