What wireless device and app to report to iPhone that freezer door has been left open

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Hardware & Accessories

Is there an accessible app to send me a notification that I've left the freezer door open? I need the time delay to be choosable, don't want a notification each time I open the door. I've seen a time-delay piece of kit which will sound an alarm after user-defined time if door open, but not sure if I'd hear it as freezer in garage.

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