# GPF Easy Diapason — Diapason

> Diapason (iPhone/iPad app by Gian Paolo Fontani.)

- Source: https://appshunter.io/ios/app/gpf-easy-diapason/id6760007666 (this page in markdown: same URL + `.md`)
- Developer: [Gian Paolo Fontani](https://appshunter.io/developer/1866631629)
- Category: Music
- Price: Free
- Age rating: 4+
- Requires: iOS 18.6 · 0 MB
- Languages: American English
- Released: 2026-03-05
- Data updated: 2026-03-11
- User reviews in markdown: https://appshunter.io/ios/app/gpf-easy-diapason/id6760007666/reviews.md

## What is 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.


## Version history (last 1 release)

### 1.0 — 2026-03-05

No release notes.

## More apps by Gian Paolo Fontani

- [Gian Paolo Fontani](https://appshunter.io/ios/app/gian-paolo-fontani/id6757398535)
- [GPF Weather System](https://appshunter.io/ios/app/gpf-weather-system/id6758885087)
- [GPF Network Console](https://appshunter.io/ios/app/gpf-network-console/id6759045565)
- [GPF Health Log](https://appshunter.io/ios/app/gpf-health-log/id6759050084)
- [GPF Registro Presenze](https://appshunter.io/ios/app/gpf-registro-presenze/id6759259886)
- [GPF Easy Calendar](https://appshunter.io/ios/app/gpf-easy-calendar/id6759526230)

All apps by Gian Paolo Fontani: https://appshunter.io/developer/1866631629

## Related topics

[gpf easy diapason](https://appshunter.io/ios/topics/gpf-easy-diapason)

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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 2026-03-11.*