DuoBox press kit
DuoBox turns iPhone Duo into an accordion. You hold the open phone like a book, with the bass buttons under one hand and the treble keys under the other, and fold it to work the bellows. Opening is pull and closing is push. The faster you fold, the louder and brighter it plays.
An accordion is the one instrument that only sounds while it folds, and folding is what iPhone Duo does that no other iPhone can.
Download the press kit (zip, 23 MB): the icon, twelve screenshots, two pictures, the preview video and a fact sheet.
Facts
- Launch: October 23, 2026, the day iPhone Duo goes on sale.
- Price: free to play. One $4.99 purchase unlocks everything. No subscription, no ads, no accounts, no data collected.
- Platform: iPhone, iOS 27 or later. Made for iPhone Duo. On other iPhones you drag the bellows with a finger.
- Languages: English, Spanish, Portuguese and German.
- Developer: Aaron Peabody, an independent developer.
Try it before launch
The public beta is open on TestFlight: testflight.apple.com/join/Twfkyj2k. It runs on any iPhone with iOS 27. The unlock is free in the beta.
What's in it
- Three accordions: a piano accordion, a three-row Norteño button accordion in five tunings, and a one-row diatonic box.
- Eleven treble registers, including Musette and Bandoneon.
- Reeds synthesized live on the phone, in stereo, with the bass on the left and the treble on the right.
- It plays closed on the cover screen as well as open.
- A song mode that lights the next key and chord.
- Recording to stereo 48 kHz, 24-bit WAV stems, with a count-in that puts each take on bar 1 in Logic Pro, and MIDI out over Bluetooth or Wi-Fi with the bellows sent as expression.
- A left-handed layout, Do Re Mi note names, and VoiceOver support.
Video
27 seconds, with sound. The full-quality file is in the press kit.
Pictures
The screenshots and video were captured in Apple's iPhone Duo simulator. You are welcome to use anything here in coverage of DuoBox.
Contact
Email aaron@aaronpeabody.dev.