I can't see why I - or anyone else - would want this. So what exactly do I gain from getting one or more of these?
It's not hard to imagine use cases. Take, for instance, an 88-year-old senior who is trying to age in place but for whom a trip to the store isn't a trivial undertaking, and who has no interest in a smartphone (and sure isn't going to see a 4" HD screen).
Boom - more detergent shows up the day after tomorrow. Iterate through typical consumables - the UI is damn simple and the button is big enough for somebody with Parkinson's to manage. That's worth the effort for the responsible child to set up.
Now take a new mom who's half-covered in crap and hasn't slept all night. Only 10 diapers left. Boom - nap time.
I'm assuming there's a reasonable "boom" sound effect here. How much are ringtones?