Foldeon: Diatonic Accordion
The phone is the bellows
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
On iPhone Duo the hinge is a bellows. Unfold, fold, and play a real diatonic accordion: push and pull notes, reeds that brighten with pressure, videos to share.
Foldeon turns your iPhone into a diatonic button accordion — and on iPhone Duo, the hinge itself becomes the bellows.
Unfold the phone and fold it again: the air moves and the reeds sing. Stop, and the sound stops, just like a real squeezebox. And like every diatonic accordion, opening and closing play different notes on the same key, so a scale runs back and forth with the bellows.
On any other iPhone, tilt the phone toward you and away to work the bellows, or drag the bellows on screen.
WHAT MAKES IT FEEL REAL
• Bellows pressure sets loudness and tone together: a gentle push is soft and dark, a firm one bright and full.
• Free-reed sound with the breath of the valves, synthesized on your iPhone — no recorded samples.
• Push and pull notes on every key, laid out like the real instruments.
• Calibrated to you: a short warm-up learns how you move and how still your phone's sensor is.
INSTRUMENTS
• Easy Accordion in G — free: eight big keys and four basses, two octaves of G major.
• With Pro: Cajun Accordion in C, Melodeon D/G, Two-Row G/C, Norteño G/C/F with 38 keys, and the 20-key Anglo Concertina C/G.
REGISTERS
Clarinet and Violin are free. Pro adds Bassoon, Bandoneón, Musette and Master.
SHARE YOUR PLAYING
Record up to a minute and Foldeon makes a vertical video with the bellows moving the way you played — ready for TikTok, Reels and Shorts. Free videos carry a small "Played on Foldeon" mark; Pro removes it.
NOTE NAMES YOUR WAY
C D E, Do Re Mi, or the German H.
FOLDEON PRO
One purchase, no subscription: five more instruments, four more registers, and videos without the watermark.
PRIVATE BY DESIGN
No account, no ads, no tracking. Your recordings stay on your iPhone until you share them. Foldeon never uses the microphone.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Ilia Filiaev, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Purchases
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Ilia Filiaev
- Size
- 12.8 MB
- Category
- Music
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
English and 11 more
- English, French, German, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Thai, Vietnamese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Foldeon Pro $5.99
- Copyright
- © 2026 Ilia Filiaev