GPF Easy Diapason

GPF Easy Diapason is a simple tuning fork app for iPhone.

It plays a continuous reference tone to help tune instruments and voices.
The interface is clean and minimal, with quick controls for sound setup.

Main features:
- Tap the 3D tuning fork to start or stop sound
- Reference frequency presets: A440, A432, A444, Baroque 415
- Base frequency control from 220 Hz to 880 Hz
- Fine tuning in cents (-50 to +50)
- Volume control
- Waveform selection: Sine, Square, Triangle, Saw
- Real time frequency display in Hz
- Version and build info in footer

Design:
- Black and white style
- Clear typography
- Focused single screen workflow for fast use

Technical notes:
- Built with SwiftUI
- Audio engine based on AVAudioEngine and AVAudioPlayerNode
- Automatic build number increment on each build

This app is made for musicians, students, choir practice, and anyone who needs a fast and reliable pitch reference on iPhone.