# PianoKeys Learn — Chord Practice & Piano Study

> Chord Practice & Piano Study (iPhone/iPad app by 应龙 张.)

- Source: https://appshunter.io/ios/app/pianokeys-learn/id6769267539 (this page in markdown: same URL + `.md`)
- Developer: [应龙 张](https://appshunter.io/developer/1514562080)
- Category: Music
- Price: Free
- Age rating: 4+
- Requires: iOS 16.0 · 0 MB
- Languages: American English, Chinese (Simplified, China)
- Released: 2026-05-14
- Data updated: 2026-06-28
- User reviews in markdown: https://appshunter.io/ios/app/pianokeys-learn/id6769267539/reviews.md

## What is PianoKeys Learn?

PianoKeys is an offline piano and chord-study tool built for learners who value precision, speed, and clean design.

SYNTHESIZED AUDIO ENGINE
PianoKeys uses a custom AVAudioEngine-based synthesizer with 8-voice polyphony and exponential decay envelopes. Every note is generated on-device in real time — no audio samples, no network dependency, zero latency.

COMPLETE CHORD LIBRARY
21 chords across three categories:
- 7 Major triads (C, D, E, F, G, A, B)
- 7 Minor triads (Cm, Dm, Em, Fm, Gm, Am, Bm)
- 7 Dominant 7th chords (C7, D7, E7, F7, G7, A7, B7)

Each chord card shows the chord symbol and full name, plays all intervals simultaneously, and highlights the constituent keys on the keyboard display.

PIANO KEYBOARD
Scrollable 2-octave keyboard spanning C2–C5. White and black keys respond to touch with spring animation and haptic feedback. Pressed keys are highlighted with accent color in real time.

PRACTICE ANALYTICS
- Daily session count
- All-time total plays
- Top 5 most-played chords by frequency

All data is persisted via UserDefaults — no account, no server, no tracking.

TECHNICAL SPECIFICATIONS
- Platform: iOS 16+, iPhone Only
- Audio: AVAudioEngine, 44100 Hz, 8-voice polyphony
- Localization: English, Simplified Chinese
- Storage: UserDefaults (local only)
- Network: None required

Delete the app to permanently remove all practice data.


## Version history (last 1 release)

### 1.0 — 2026-05-14

No release notes.

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All apps by 应龙 张: https://appshunter.io/developer/1514562080

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-28.*