What exactly were you bale to build in 20 minutes?

Me, and photo editor tool to semi-automate a task of digitizing a few dozen badly scanned old physical photos for a family photo book. Needed something that could auto-straighen and auto-crop the photos with ability to quickly make manual adjustments, Gemini single-shotted me a working app that, after few minutes of back-and-forth as I used it and complained about the process, gained full four-point cropping (arbitrary lines) with snapping to lines detected in image content for minute adjustments.

Before that, it single-shot an app for me where I can copy-paste a table (or a subsection of it) from Excel and print it out perfectly aligned on label sticker paper; it does instantly what used to take me an hour each time, when I had to fight Microsoft Word (mail merge) and my Canon printer's settings to get the text properly aligned on labels, and not cut off because something along the way decided to scale content or add margins or such.

Neither of these tools is immediately usable for others. They're not meant to, and that's fine.

My buddy and I are writing our own CRUD web app to track our gaming. I was looking at a ticketing system to use for us to just track bug fixes and improvements. Nothing I found was simple enough or easy enough to warrant installing it.

I vibe'd a basic ticketing system in just under an hour that does what we need. So not 20 mins, but more like 45-60.

I built a small app to emit a 15 kHz beep (that most adults can't hear) every ten minutes, so I can keep time when I'm getting a massage. It took ten minutes, really, but I guess it's in the spirit of the question.

For 20 minutes of time, I had a simple TTS/STT app that allows me to have a voice conversation with my AI assistant.