Last year I wrote about the 1.1 update of BPM Analyzer - an app I’ve been working on for the last 3 years. It’s a cross-platform app that started as a music management tool, it now has local music analysis (with automatic ID3 tag writing, which was the main feature I made this for), a metronome tool and a live audio analysis feature - letting you get the tempo of a song using your device’s microphone. Update 1.1 brought iOS/iPadOS support, a watchOS extension, analytics and localization. I wrote about it here.

In the 1.2 update I rebuilt and optimized the tempo detection algorithm, combined the file and live audio analyzers into one, made it much more accurate and 4.4 times faster, got to try out and make use a brand new Apple framework:

Music Understanding

Music Understanding is a recent API (iOS 27.0+) that can analyze audio content and extract music information from it - like the rhythm, pace, loudness, key, and instrument activity. It was introduced at this year’s WWDC and I was very excited to try it out since on paper it was just the right thing for my app.

I tried the new framework thinking it could replace my own beat detection algorithm, keeping the app optimized and cross-platform. However, it turned out that MU does not work in that way. It could accurately predict song’s mood, but it doesn’t return an actual value for the BPM. I managed to find a use for the framework - I use it as a “second opinion” - a way to have another check after the song’s been analyzed.

It’s quite exciting to be able to actually try out a new thing Apple just introduced (it’s been almost half a year since the announcement, which in iOS developer’s timeline can be considered pretty quick), and it’s actually useful for an active project of mine. Sweet!

I’ve written a more detailed article about how it works here: https://techgrid.media/builder-insights/apple-just-made-beat-detection-an-api-do-ios-developers-still-need-to-understand-dsp/. I thought about diving deep into how the analyzer actually works, but it’s worth a whole article on itself, including live audio analysis. Maybe next time.

New App Store features

With this update I tried another new thing, introduced at this year’s WWDC - new App Store features like App Header image and Search results image - both are promotional instruments that let you make you app stand out. They look

App header	Search results

To be honest, I’m so stoked about this app, all the musical aspect of programming and an ability to build something so complex, yet so simple in its nature, that I’ll surely write more about it when I have enough time.