Google Calendar syncs directly. Android or iPhone, it makes no difference. They connect once, and after that anything you change shows up on their calendar straight away — nobody has to refresh anything.
A calendar for each group. Every group now has its own month view. Open it from “Group calendar” in the top bar. It is meant for the tablet on the kitchen wall, where everyone can just look up and see it.
Each task decides whether it goes on that wall. Some things should not be readable by whoever walks past. Untick “show on the group calendar” on that task and it stays off.
They can report “done” straight from the calendar. Opening the event on their own phone shows a line that says “✓ Done? Tap here to tell them”. One tap and you know. They never sign up for anything and never install anything.
A notification bell. Top right. When somebody reports something finished, a red number appears; open it to see who, what and when. Your own ticks on the website do not count — those are things you did, not news.
The date field says what it means. The old wording was easy to misread. It now simply asks when the task is next due.