

Oh, many years ago I had a baby monitor that included a pressure mat. If it detected no movement for a while (it was sensitive enough to detect breathing) it set off an alarm.
Although if such a thing exists today, it probably requires an app and a subscription. Enshitification.
BASIC uses (used?) it to declare variables. (I don’t know if earlier languages did.)
Not that that’s a reason for other languages to copy it.