Unpopular opinion: the microwave popcorn button.
Let me introduce you to Technology Connections report on the matter: www.youtube.com/watch?v=Limpr1L8Pss
What's the deal with the popcorn button?

Try it. You know you want to.Referenced Videos:The Antique Microwave Oven that's Better than Yourshttps://youtu.be/UiS27feX8o0And the follow-up to that oneht...

YouTube
Can I please get a tldw? I love the idea of technology connections. But who has the time?

I watched a while ago so I may misremember.

Cheap ones are just a timer that works for most common microwave popcorn packages.

Good ones detect the first popped kernel and then go for another 30s, as stated on most microwave popcorn packages

iirc there are also some that detect humidity and infer when to stop from that somehow
That might be how the first kernel popping gets detected.