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.