# RacquetTune - String Tension — Racquet optimization tools

> Racquet string tension and performance analysis tool for racket sports. (iPhone/iPad app by Sten Kaiser.)

- Source: https://appshunter.io/ios/app/racquettune-string-tension/id365729342 (this page in markdown: same URL + `.md`)
- Developer: [Sten Kaiser](https://appshunter.io/developer/309325742)
- Category: Sports, Utilities
- Price: $2.99
- Rating: 4.60/5 from 474 App Store ratings · 172 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 11 MB
- Languages: American English
- Released: 2010-04-07
- Data updated: 2026-08-29
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/racquettune-string-tension/id365729342/reviews.md

## What is RacquetTune?

Listen to your racquet and perfect your game!

RacquetTune ensures that your racquet is ideally suited to your style of play. Simple and straightforward to use, the app uses the sound generated by tapping the strings to calculate the tension with high accuracy. In addition, the interactive swingweight calculator aids in customizing your racquet to fit your own stroke pattern, while the stiffness calculator allows you to simulate different racquet configurations. 

RacquetTune not only makes it easier to decide when it is time to restring, it is also an invaluable tool when testing different racquets and strings and in identifying which of your racquets is best suited for different types of games. RacquetTune also allows you to check whether your stringer is consistent in his work. 
RacquetTune includes the following user-friendly tools:

Tension measurement 
- Quickly determines the tension and stringbed stiffness. 
- Able to detect changes in tension as small as 0.1 kg/0.2 lb.
- An accuracy indicator ensures results are consistent. 
- Graphical presentation of sound waves helps you find the ideal way of tapping the strings. 
- Settings can be customized to serve tennis, squash, racquetball and badminton racquets, respectively. 
- View the tension history for each racquet as a list or a graph.
- Email a spreadsheet with test data.

Swingweight calculator 
- Add as many weights as you wish to the frame. 
- Move and change weights to visualize how swingweight, balance and sweet spot location are affected.
- Enter target values for the racquet and let RacquetTune distribute the weights automatically.

Stiffness calculator 
- Simulate various racquet and string configurations
- Vary tension, string type and racquet head size. 
- Shows load-displacement curves, stiffness and elastic energies 
- Handles the large deformations encountered in actual play 

View a demo video at racquettune.com

RacquetTune has been featured in tennis magazines in USA, Italy, France, Germany, Sweden and Norway. 

"The app is very, very impressive. I get more tension diagnostic questions than just about anybody in the universe, so this is a very good thing to be able to recommend." 
Jonathan Wolfe 
US Racquet Stringers Association

Note, that the actual string tension in the racquet and the setting seen on a stringing machine are two different things and therefore incomparable - more information can be found at racquettune.com.

## Key features

- String tension measurement
- Swingweight calculator
- Stiffness calculator
- Racquet configuration simulation
- Tension history tracking
- Export test data

## Chart rankings

- #19 in Top Paid · Sports (US App Store)

## What do users think of RacquetTune?

Overall sentiment: neutral

**Pros**

- 🔒 Consistent and precise measurements
- 📊 Useful for tracking tension loss over time
- 🔧 Helpful for customizing rackets
- 📋 Good for logging string usage and tension
- 🔍 Accurate enough for most stringing needs

**Cons**

- 🐛 Inconsistent or inaccurate readings
- 🔍 Not precise enough for some users
- 🤔 Complicated setup/calibration process
- 🔇 Requires a quiet environment to work properly
- 🔌 Stops working after some time

**Commonly reported bugs**

- App crashes when trying to delete rackets
- String factor database not working properly
- Inconsistent readings on the same racket
- Struggles with rackets with built-in dampers

**Most requested features**

- Add more strings to the database
- Allow logging of playing hours
- Improve history/graphing features
- Support for hybrid string setups
- Add racket database for easier setup

## Recent user reviews (10 of 172)

All indexed reviews: https://appshunter.io/ios/app/racquettune-string-tension/id365729342/reviews.md

### 5/5 — great tool

*2026-06-09*

been using it for years. great that it has note functions. I can know: when tension drops, How well I strung the racket and I can rate the setup for the future. Especially good for a nerd like me that tries a lot of different setups

### 1/5 — No reading

*2026-06-06, version 7.7*

I’ve followed the instructions in their YouTube video and can never get a reading for tension. Wasted money!

### 5/5 — Works well

*2026-04-05, version 7.7*

Good for tracking tension drop

### 5/5 — 使えるようになった。

*2026-04-03*

アップデートありがとう。

### 1/5 — Stopped working

*2026-03-29*

Seems to have stopped working (does not detect sounds even though microphones access granted) on my iPhone 17 with iOS 26.4.  Please update !

### 1/5 — Stopped picking sound after iOS 26.4 update

*2026-03-28*

Hey Sten, would you please update the app? The app was still picking up my tapping before the 26.4 update. It's completely dead now.

### 1/5 — Komplett unbrauchbar

*2026-02-01*

Nicht kaufen! Ich hatte gedacht aufgrund vieler guten Bewertungen, dass die Personen, die eine schlechte Bewertung abgegeben haben die Einstellungen für das eigene Racket nicht genau eingegeben haben. Ich hab die Schlägerkopfgröße, Besaitungsmuster, die Saiten selber angegeben, und den Dämpfer entfernt. Habe heute einen Schläger mit 22kg bespannt und das Gerät zeigt 13,8kg an. Spart euch die 3€!

### 1/5 — 4lbs off

*2025-08-02, version 7.6*

Never accurate

### 5/5 — お手軽に測定できる

*2025-07-12*

テンションの落ち具合を手軽に測定でき便利です。が、アップデートのせいなのか過去のデータが全て消えてしまいました。。。元に戻してください。

### 5/5 — Great to understand tension

*2025-05-28*

Great to understand how tension declines, not accurate but precise!.
Keep notes on how it played and use the tension reported by the app as a reference. 
I use RPM Blast 17, pre-stretched 15 sec, strung at 55:53 and app reports 45.4, still very useful since these measurements are very consistent. I use this app now to keep a log of my string usage and tension. I recommend it!

## Frequently asked questions about RacquetTune

### What does RacquetTune do?

RacquetTune is a mobile application designed to help you optimize your racquet for your playing style. It uses the sound generated by tapping your racquet strings to accurately calculate string tension and stringbed stiffness. It also includes tools for analyzing swingweight and racquet stiffness.

### What are the key features of RacquetTune?

Key features include precise tension measurement with an accuracy indicator, a swingweight calculator to visualize the impact of added weights, and a stiffness calculator to simulate various racquet and string configurations. It also allows for tracking tension history and exporting test data.

### How much does RacquetTune cost?

Based on the provided information, RacquetTune is a paid application. There are no mentions of free versions, subscriptions, or in-app purchases for core functionality.

### What racquet sports is RacquetTune compatible with?

RacquetTune is designed to be used with racquets for tennis, squash, racquetball, and badminton. The app's settings can be customized to serve each of these sports specifically.

### How can RacquetTune help me improve my game?

By accurately measuring string tension, RacquetTune helps you ensure your racquet is strung to your preferred specifications, impacting feel and performance. The swingweight and stiffness calculators allow you to fine-tune your racquet's characteristics to match your stroke pattern and playing style, potentially leading to better control and power.

## Version history (last 5 releases)

### 7.7 — 2026-04-02

This update from Apple will improve the functionality of this app. No new features are included.

- Fixed the problem with detecting sound on iOS 26.4 and later.
- Fixed an issue with contributing strings to the online database.

### 7.6 — 2020-02-28

- All weights in swingweight can be removed with a long press on the +Weight button.
- A problem with uploading the database has been fixed.

### 7.5 — 2019-12-19

- Easier to pick strings in the online DB.
- A sound detection problem on some device has been improved/fixed .

### 7.4 — 2019-09-25

iOS 13 compatibility improvements (dark mode will come later).

### 7.3 — 2019-04-09

Picking a racquet will automatically pick the string used last time.

## Apps similar to RacquetTune

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [RacketTune](https://appshunter.io/ios/app/rackettune/id6746103106) | 3.5 (2) | Free | Sports |
| [stringster for Tennis 2.0](https://appshunter.io/ios/app/stringster-for-tennis-20/id6446997820) | 1.8 (5) | Free | Sports |
| [String GOAT - for tennis](https://appshunter.io/ios/app/string-goat-for-tennis/id6444395925) | 4.1 (8) | Free | Sports |
| [String Master - Tennis Log](https://appshunter.io/ios/app/string-master-tennis-log/id6757102423) | 5.0 (7) | Free | Sports |
| [RacquetTuner](https://appshunter.io/ios/app/racquettuner/id6755720177) | 1.0 (1) | Free | Sports |
| [Direct Tennis](https://appshunter.io/ios/app/direct-tennis/id1613818171) | 3.8 (16) | Free | Sports |

## More apps by Sten Kaiser

- [SeeLevel - visual clinometer](https://appshunter.io/ios/app/seelevel-visual-clinometer/id333213338)
- [SpeedClock - Video Radar](https://appshunter.io/ios/app/speedclock-video-radar/id400876654)
- [SwingTool - Swing Weight](https://appshunter.io/ios/app/swingtool-swing-weight/id408209116)
- [SprintTimer - Photo Finish](https://appshunter.io/ios/app/sprinttimer-photo-finish/id430807521)
- [FitnessMeter - Test & Measure](https://appshunter.io/ios/app/fitnessmeter-test-and-measure/id477488986)

All apps by Sten Kaiser: https://appshunter.io/developer/309325742

## Related topics

[raqet](https://appshunter.io/ios/topics/raqet) · [racquet tune](https://appshunter.io/ios/topics/racquet-tune) · [stringster](https://appshunter.io/ios/topics/stringster) · [racket tune](https://appshunter.io/ios/topics/racket-tune) · [racket tension](https://appshunter.io/ios/topics/racket-tension) · [the racquet](https://appshunter.io/ios/topics/the-racquet)

---

*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 2026-08-29.*