Christian Johnson

inTune is a professional-grade iOS tuner application that delivers real-time pitch detection with studio-quality accuracy. Built entirely in SwiftUI with modern iOS development practices, the app provides musicians with precise tuning feedback through an intuitive, visually appealing interface.

Demo

App Store deployment planned for 2025

Features

Real-time Pitch Detection: ±1 cent accuracy using advanced audio processing
Chromatic Note Recognition: Automatic detection across full chromatic scale with octave display
Visual Tuning Meter: Custom-built cents meter with color-coded accuracy zones
Configurable Update Rates: Adjustable detection frequency (1x to 3x speed)
Universal Instrument Support: Works with guitar, violin, piano, brass, woodwinds, and more
Modern SwiftUI Interface: Smooth animations and responsive design
Offline Functionality: No internet connection required

Technologies Used

Swift 5.9 / SwiftUI
AVFoundation (Audio session management)
Combine Framework (Reactive programming)
Tuna Library (Pitch detection engine)
MVVM Architecture
iOS 15.0+

Technical Highlights

Architecture

Clean MVVM pattern with reactive data binding
Protocol-oriented design for testability
Modular component structure ready for App Store deployment

Audio Processing

// Configured AVAudioSession for optimal microphone input
try audioSession.setCategory(.record, mode: .measurement, options: [])

// Real-time pitch detection with delegate pattern
func pitchEngine(_ engine: PitchEngine, didReceive result: Result<Pitch, Error>)

Music Theory Implementation

Equal temperament calculations using A4=440Hz standard
Logarithmic frequency-to-pitch conversion algorithms
Precise cents deviation measurement (100 cents = 1 semitone)

SwiftUI Components

Custom CentsMeterView with geometric calculations
Responsive layouts using GeometryReader
@Published properties for automatic UI updates

Key Challenges Solved

Cross-platform compatibility: Simulator fallback for testing without microphone
Audio session management: Proper lifecycle handling and permission requests
Mathematical precision: Implemented equal temperament tuning calculations
Performance optimization: Efficient timer management for battery life

Code Quality

Comprehensive error handling with Result<Success, Error> patterns
Memory safety using [weak self] to prevent retain cycles
Clean separation of concerns with single-responsibility components
Extensive inline documentation and architectural comments

Future Enhancements

Instrument-specific presets (guitar, bass, violin tunings)
Alternate temperament support (baroque, world music scales)
Strobe tuner and analog needle display modes
Settings panel for reference pitch customization
App Store deployment with premium features