With my washing machine, I press the button. It'll say "no", drain down the drum so the water doesn't fall out when the door opens, then say "yes" and the door unlocks.

Apps used: 0.

Would be useful if the machine could select and load the washing itself from the basket, I'd use that app.

but why? I mean if I'm doing laundry I'm within 50 ft of the machine generally? I have never needed to do such an operation or can think of a situation where the added complexity merits the addition of wifi and security threats of a Russian hacker trying to mine etherium on my dish washer.

I can't claim to know every Miele there is but both an early 80s and an early 2010s Miele has pause/continue buttons. On the 2010 one it even looks like a play-pause button.