For our first child in 2011, we were struggling to agree on a name, so I created a baby names app that tried to learn the kinds of names you liked, based on sounds, meanings, origins etc. It was my first real attempt at any sort of machine learning, and while we eventually reverted to the much simpler algorithm of my wife putting her foot down, I decided to package it up and launch it on the Mac app store. It was briefly the number one lifestyle app in the UK, and could more or less pay for its own Google Ads, but I killed it off when sandboxing started to make NSDocument based apps break. Some screenshots survive:
https://lemonwatcher.com/baby-names-1.png
https://lemonwatcher.com/baby-names-2.png
https://lemonwatcher.com/baby-names-3.png