Gentle chime every 10 s, separate from phone reminders. Test beep
On each phone that should get alerts: install the free ntfy app, then scan that phone's code (or tap + and enter the topic). Warning, Danger and unattended alerts include a snapshot of the kitchen.
Up to 5 addresses. Limits to prevent flooding: the same alert at most once per 5 min (getting worse always sends), 10 alerts per hour, 30 emails per day.
Keep this device plugged in, screen on, app in front. The screen is kept awake while watching. This is a helper, not a smoke detector: keep a real smoke alarm.
This photo will be uploaded to the KitchenWatch developer to improve detection. Don't include people's faces if you can avoid it.