TromPhone, a Trombone for Your Phone
A few months ago I had a silly idea of making a mobile app that used the accelerometer to track the slide motion for playing a virtual trombone. Just wanted to share the story of bringing it to fruition here on hn. I started out spending a couple days trying to get something cross-platform going in Flutter, but it soon became clear that wasn't the best fit, seeing as I'd need native hooks for most of what the app needed to do, and it wasn't yet clear it'd be possible at all. So I switched to making it an iOS app in Swift. The accelerometer data turned out to be not nearly accurate enough to…
TromPhone, a Trombone for Your Phone launched on December 7, 2022 with 58 votes, #1,020 of 3,688 launches that month and more than 90% of that year's launches.
In plain words
TromPhone is an iOS app that lets users play a virtual trombone on their phone using augmented reality. The app tracks hand movement through the device's camera to simulate trombone slide motions, allowing users to produce different tones by adjusting their hand position. Built in Swift, it combines AR technology with musical interaction for a playful, music-making experience on mobile devices.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
A few months ago I had a silly idea of making a mobile app that used the accelerometer to track the slide motion for playing a virtual trombone. Just wanted to share the story of bringing it to fruition here on hn. I started out spending a couple days trying to get something cross-platform going in Flutter, but it…
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