Fold Accordion
by Special Glasses LLC
- Music
- Paid
- Small & simple · 100
- Rating
- 0.0
- 0 ratings
- Top 97%among 32 Music apps
- Last update
- Oct 22, 2026
- Version 1.0
- Size
- 19 MB
- Category
- Music
- Tracked since
- Oct 24, 2026
Estimated revenue
A model estimate with a likely range, not a reported figure.
No estimate. Apps outside the grossing charts, and some countries, have no reliable rank-to-revenue curve, so we show nothing rather than a guess.
How this estimate is made
Rank: we take the app's best Top Grossing rank on the latest chart day. Category ranks are converted into an equivalent overall rank, because a #10 in Finance earns far less than a #10 overall.
Curve: that equivalent rank is read off a rank-to-revenue curve anchored on public company revenue and market-data reports for the US iPhone App Store.
Country: the curve is scaled per country (Japan is roughly a third of the US, Türkiye under 1%). Where we have no scale, such as China, there is no estimate.
Range: the likely range widens with country, category and chart depth. It is a plausible span, not a statistical confidence interval.
Not included: ads, payments outside the App Store, and any difference between gross sales and what the developer keeps. Low confidence means indirect data; medium means several independent sources agree.
Full methodScreenshots
As shown on the App Store listing.
About this app
Text from the App Store listing.
Fold Accordion is an accordion you play on your iPhone. On iPhone Duo, the hinge is the bellows. Open and close the phone to push air, and press the keys on screen to pick the notes.
On other iPhones, swing the phone side to side to pump the bellows. Or pick Touch, and the air flows while you hold a key.
PLAY
- Piano keys for the right hand, C4 to G5
- Bass notes F, C, G, D, A, E and chords FM, CM, GM, Dm, Am, Em for the left hand
- Play several keys at once
- Move faster to play louder
- A quick change of direction dips the air, like a real bellows
- Pick how you play: Fold, Swing, or Touch
LEARN
- 24 public-domain songs, from Ode to Joy to Jingle Bells
- Learn mode lights up the key to play. The song waits until you play it.
- Start with the melody while the bass plays along. Then turn on Both hands to play the bass and chord buttons too.
- Or pick Listen, and the song plays itself while the keys light up
- Auto bellows pumps the air for you, so you can focus on the keys
SOUNDS
- Seven sounds: Accordion, Button accordion, Italian accordion, Bandoneon, Reed organ, Harmonica, and Reed synth
- Accordion and Button accordion are recorded from real accordions
- Pick a sound and it plays a short tune
ALSO
- Light and dark mode
- No network, no account
Pay once. No ads. No subscription. No in-app purchases.
Made for iPhone Duo. Works on iPhone with iOS 26 or later.
Rank history
Daily position in the UK charts. #1 is at the top.
- Best rank
- #10
- Current rank
- #11
- Days charting
- 2 of 7
On the charts today
Small & simple score
How realistic it is for a small team to build something like this.
100/100
Small & simple
- Developer size100% · 25
Developer: 1 app on the charts
- Audience size100% · 20
Ratings: 0
- App size100% · 10
Size: 19 MB
- Price model100% · 15
Price model: paid
- Demand proof100% · 30
Best rank #1, 15 countries
An indicator, not a fact. We can't see team size. Calculated Oct 25, 2026 · method i2
How the score worksVersion history
- 1.0LatestReleased Oct 22, 2026