# Grainote - Guitar Tuner — Guitar Tone & Tuning Tracker

> Guitar Tone & Tuning Tracker (iPhone/iPad app by Yuji Sakurai.)

- Source: https://appshunter.io/ios/app/grainote-guitar-tuner/id6768381569 (this page in markdown: same URL + `.md`)
- Developer: [Yuji Sakurai](https://appshunter.io/developer/1879008639)
- Category: Music, Productivity
- Price: Free
- Age rating: 4+
- Requires: iOS 13.0 · 60 MB
- Languages: American English
- Released: 2026-07-06
- Data updated: 2026-09-04
- User reviews in markdown: https://appshunter.io/ios/app/grainote-guitar-tuner/id6768381569/reviews.md

## What is Grainote?

GRAINOTE is a tuner and acoustic data tracker for guitarists.

Every time you tune, GRAINOTE automatically records the acoustic characteristics of your strings, building a unique "acoustic fingerprint" of your guitar over time.

【Key Features】

■ Precision Chromatic Tuner
Detects the fundamental frequency of each string in real time, supporting precise tuning down to the cent.

■ Acoustic Profile Recording
Each tuning session automatically saves:
· Fundamental strength (dB)
· 2nd–5th harmonic ratios
· Spectral centroid (brightness)
· Sustain score

■ Harmonic Spectrum Display
Play a string to see its frequency spectrum in real time — visualize the harmonic structure of your guitar's tone.

■ Tuning History
Browse past session data and track how your strings' acoustic properties change over time.

■ Model Comparison (Coming Soon)
Compare your data anonymously with other players using the same brand and model. Discover what makes your guitar unique.

■ Multi-Guitar Management
Register and manage multiple guitars with details like brand, model, and string gauge.

【Privacy】
Only acoustic numerical data is collected (harmonic ratios, frequency values, sustain scores, etc.). Audio is never recorded or stored. All data is processed anonymously.

A4 reference pitch is adjustable from 432 Hz to 446 Hz. Microphone access is required.


## Version history (last 5 releases)

### 1.0.11 — 2026-09-03

■ Bug Fixes
· Fixed an issue where the microphone could start unintentionally during onboarding
· Fixed an issue where guitar information could be registered multiple times when completing the survey

### 1.0.10 — 2026-08-27

■ Improvements
· Refreshed the app's visual design to align with the latest Material Design
· Added guidance showing which string to pluck next while tuning
· Prevented accidental double-taps on the record button
· Fixed an issue where tuning data was sometimes not saved correctly

### 1.0.9 — 2026-08-15

■ Improvements
· You can now skip the initial survey
· Cleaned up the tuner screen so key information is easier to see
· Improved usability of the model comparison screen
· Improved support for screen readers (VoiceOver, etc.)

### 1.0.8 — 2026-08-14

■ Improvements
· Improved the on-screen guidance so it's clearer when to pluck a string

### 1.0.7 — 2026-08-11

■ Improvements
· Improved tuning accuracy for the low E string
· The app now remembers your selected guitar between sessions
· Made the same-model comparison feature easier to unlock

■ Bug Fixes
· Fixed an issue where the app could become unresponsive when the microphone was unavailable

## More apps by Yuji Sakurai

- [VocalLens - Voice Coach](https://appshunter.io/ios/app/vocallens-voice-coach/id6759490642)
- [LiarDoku - Liar Sudoku Puzzle](https://appshunter.io/ios/app/liardoku-liar-sudoku-puzzle/id6760775677)
- [DropCraft - Physics Puzzle](https://appshunter.io/ios/app/dropcraft-physics-puzzle/id6761014269)
- [SwingScope](https://appshunter.io/ios/app/swingscope/id6761335450)
- [BUNKER PROTOCOL: Reactor Core](https://appshunter.io/ios/app/bunker-protocol-reactor-core/id6762374097)

All apps by Yuji Sakurai: https://appshunter.io/developer/1879008639

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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 2026-09-04.*