# Koto Tuner - こと — Precise & Easy Plus metronome

> Koto tuner app with visual pitch indicators and multiple tuning modes. (iPhone/iPad app by Hsing-Fu Hsueh.)

- Source: https://appshunter.io/ios/app/koto-tuner/id1295474780 (this page in markdown: same URL + `.md`)
- Developer: [Hsing-Fu Hsueh](https://appshunter.io/developer/1103119781)
- Category: Music, Utilities
- Price: Free with in-app purchases
- Rating: 3.00/5 from 1 App Store ratings · 5 written reviews indexed
- Age rating: 4+
- Requires: iOS 10.0 · 49 MB
- Languages: American English, Japanese, Chinese (Simplified, China), Chinese (Traditional, Taiwan)
- Released: 2017-10-17
- Data updated: 2026-06-02
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/koto-tuner/id1295474780/reviews.md

## What is Koto Tuner?

[Koto Tuner] 
      
      The simple user interface with noise filtering can help you tuning the 13 strings without any setting while activating the APP.  When you pull the Koto string, the pitch will be shown on the panel for the individual string by indicating signal high or low. 


[Function Description]
	▪	Calibrate  Piano Sound : Click on an open string then calibrate the sound with your Koto.
	▪	A4 Frequency adjustment: choose 428~452 frequencies for A4 string.
	▪	Total 18 kinds of tuning modes are available.
	▪	The scale for precision tuning is 5 cents for every sub-bit.  The blue line represents the open strings start from.  The green arrow means pitch is accurate and it will turn white once the pitch difference exceeds more than a sub-bit.  
	▪	The complete function, will visually tell you the pitch is good or not by lighting green or white.  Users can easily adjust the string by the lighting arrow shown on the scale.


       We welcome you to feedback us for any questions, suggestions and comments regarding this APP.

## Key features

- Noise filtering for accurate tuning
- Visual pitch indicators
- Calibrate piano sound
- A4 frequency adjustment
- 18 tuning modes
- Precision tuning scale

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| All Function&No Ad | $1.99 | one-time |


## Recent user reviews (5 of 5)

All indexed reviews: https://appshunter.io/ios/app/koto-tuner/id1295474780/reviews.md

### 1/5 — アプリを開くと異音

*2025-10-28, version 3.1*

アプリを開くと異音がします。1年ぶりに使おうと再ダウンロードしたら何度もアプリを開き直しても異音。
サービス辞めちゃったんですか？

### 3/5 — Ok for tuning by ear, but buggy

*2025-05-25*

It’s useful to hear and see the names of different traditional scales for koto tuning, but it’s not useful to see if your notes are flat or sharp, and audio bugs make it hard to use as intended. 

There is constant buzzing audio feedback when using the app, for the tuner (which disrupts tuning) and also the metronome. It looks like when I have tuning set to 442 hz, the app always registered the note as sharp. When I try to set it to 440 hz, the app automatically jumps back to 442. 

As feedback, it would be helpful if the names of the scales had an option to read them in romaji or furigana.

### 5/5 — すごい

*2019-08-29, version 3.0*

とても正確で、琴の全てのチューニングが、このアプリ１つでできます。平調子以外のものが欲しければ、買えばいい。240円で全ての機能が手に入るのは、安いと思う。琴のチューナー持ち歩かなくていいし、それを買うよりものすごく安いよ。

### 1/5 — 使えません

*2018-12-04, version 3.0*

お金払わないと使えないし、なぜか迷惑メールが届くようになった

### 1/5 — 使えない！

*2018-07-20, version 2.3*

バナー広告の問題解決して無い。
平調子しか使えない！
¥240払わなきゃ使えないなら無料じゃないでしょ！

## Frequently asked questions about Koto Tuner

### How does Koto Tuner help me tune my instrument?

Koto Tuner uses a simple interface with noise filtering to display the pitch of each string. Visual indicators show if the pitch is high, low, or accurate, guiding you to make precise adjustments.

### What tuning modes does Koto Tuner offer?

Koto Tuner provides a total of 18 different tuning modes, allowing for flexibility in how you tune your koto. It also supports A4 frequency adjustment between 428-452 Hz.

### Is Koto Tuner accurate for tuning?

The app features a precision tuning scale where 5 cents represent each sub-bit. A green arrow indicates accurate pitch, and it turns white if the difference exceeds a sub-bit, providing clear visual feedback.

### Can I calibrate the sound with Koto Tuner?

Yes, Koto Tuner allows you to calibrate the sound by clicking on an open string and then calibrating the sound with your koto. This helps ensure accurate readings for your specific instrument.

### What devices is Koto Tuner available on?

Koto Tuner is available for iPhone, iPad, and iPod devices. It was last updated on October 21, 2019, with version 3.1.

### What is the age rating for Koto Tuner?

Koto Tuner has an age rating of 4+, making it suitable for a wide range of users. The app is free to download and use.

### Does Koto Tuner have ads?

No, Koto Tuner does not contain advertisements. The app is free to download and use, with optional in-app purchases.

### How often is Koto Tuner updated?

Koto Tuner was last updated on October 21, 2019, to version 3.1. While there haven't been recent updates, the app remains functional for its intended purpose.

## Version history (last 5 releases)

### 3.1 — 2019-10-21

Bug fixes for iOS 13

### 3.0 — 2018-11-25

Add metronome

### 2.3 — 2018-05-22

Resolve banner ads cannot be removed immediately.

### 2.2 — 2018-05-16

Add Reset Button.

### 2.1 — 2018-01-06

Correction of the pitch index residue problem

## Apps similar to Koto Tuner

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Sanshin Tuner Pro](https://appshunter.io/ios/app/sanshin-tuner-pro/id1356223506) | — | $9.99 | Music |
| [Sanshin Tuner Basic](https://appshunter.io/ios/app/sanshin-tuner-basic/id1437345765) | — | Free | Music |
| [Vocal Analyzer Z](https://appshunter.io/ios/app/vocal-analyzer-z/id1670800089) | — | $1.99 | Music |
| [e-scope 3-in-1](https://appshunter.io/ios/app/e-scope-3-in-1/id660574048) | 3.0 (1) | $1.99 | Music |
| [Soniq Viewer](https://appshunter.io/ios/app/soniq-viewer/id448343005) | 5.0 (1) | $1.99 | Music |
| [Touch Tuner](https://appshunter.io/ios/app/touch-tuner/id714823553) | 4.1 (7) | $0.99 | Music |

## More apps by Hsing-Fu Hsueh

- [Erhu Tuner - Pitch](https://appshunter.io/ios/app/erhu-tuner-pitch/id1103119782)
- [Violin Tuner - Pitch](https://appshunter.io/ios/app/violin-tuner-pitch/id1185155196)
- [Viola Tuner - Pitch](https://appshunter.io/ios/app/viola-tuner-pitch/id1193544408)
- [GuQin Tuner - Pitch](https://appshunter.io/ios/app/guqin-tuner-pitch/id1268477087)
- [PiPa Tuner-Tuner for PiPa](https://appshunter.io/ios/app/pipa-tuner-tuner-for-pipa/id1268904834)
- [SanXian Tuner-Tuner SanXian](https://appshunter.io/ios/app/sanxian-tuner-tuner-sanxian/id1268910012)

All apps by Hsing-Fu Hsueh: https://appshunter.io/developer/1103119781

## Related topics

[kotona](https://appshunter.io/ios/topics/kotona)

---

*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 2026-06-02.*