Little programs or scripts or automations you’ve created ad-hoc to solve a particular single use case
I have lots of shortcuts i make on my phone and I have one i love that detects when bluetooth accidentally or purposefully disconnects from my speaker and reconnects it and fixes a playback glitch so its back to playing properly
Back over 10+ years ago on the original raspberry pi, I made a butler program. Every hour on top of the hour, it would use espeak to say what my schedule was, the current internet usage (there was max usage of 100gb) and a couple of other things. It worked really well for years.