[joshday]

I made a guitar tuner iOS app!

I didn't particularly like existing options and it was a fun way to learn some Swift/SwiftUI/AudioKit, all of which are outside the typical programming I do for work (Julia). It was also a great experience to "launch" a product. I sell a few units per month so it also nets me a hilariously small passive income.

https://oneclicktuner.com

[patwolf]

Very nice. Guitar tuner apps are one of those things that should be really basic, but popular ones tend to get more bloated over time as they try to monetize it. You can buy a hardware tuner for what some apps charge.