Some of mine:

* A program to monitor a webcam aimed at a bird house to see if any bird occupies it

* A program to periodically send a 10 Hz tone to prevent my speakers from falling asleep, so that I don't miss the first part of a Teams call

* A program to monitor a MiFlora humidity sensor to alert me when my plants need watering

* A program to estimate number of cars and their speed in my street from a webcam

* A program to sync a subtitle with correct timing with a subtitle in the correct language

All hacked together Python scripts; I'm not a programmer