Comparison

String Tension AI vs Goodminton

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

String Tension AI

This app uses your iPhone's microphone to measure the tension of your racquet strings. It tracks tension decay over time, offers personalized restring recommendations, and provides a comprehensive string toolkit for serious players.

Highlights
  • Measure string tension with iPhone microphone
  • Track tension decay over time
  • Personalized restring recommendations
  • String database and player setups
  • Playing session tracking
  • Cost tracking for restringing
Features
Read full description

Measure tennis string tension. Make your next restring count. String Tension AI is an iPhone app for measuring tennis string tension, tracking tension loss and choosing when to restring. Tap your racquet's stringbed near the microphone to get a tension estimate in kg or lb. No external hardware needed. AVAILABLE IN 8 LANGUAGES English, German, French, Italian, Spanish, Brazilian Portuguese, Simplified Chinese and Danish. The app follows your iPhone's language, with regional dates, numbers and currency. Choose a different app language in iOS Settings. MEASURE AND TRACK FOR FREE • Take unlimited measurements for one racquet and review your 20 most recent readings. • Get live quality coaching, cross-checks across multiple taps and calibration against a known reference tension. Readings that do not hold up are set aside from guidance. • Follow How to Measure with narration and captions in all eight languages. • Check String Health, tension trends and restring guidance based on usable readings. • Track full beds, hybrids, custom strings and separate main/cross tensions. CONNECT YOUR PLAYING AND STRING HISTORY • Log session duration, intensity and racquet; review the calendar, set goals, build streaks and celebrate milestones. • Review and import tennis workouts from Apple Health for free, with possible duplicates flagged. Optional heart-rate access can suggest intensity without saving heart-rate data. • Open My Stringers from the Strings hub to manage contacts, favorites, archives and restring history for free. • Browse expanded racquet and string catalogs and ATP, WTA and Legends setups. Save favorite strings, add ratings and discover daily tennis facts. • Share visual cards for supported string-health, tension, string-job and achievement highlights. GO FURTHER WITH PRO • Unlimited racquets and string setups, full measurement history and Measurement Insights. • Advanced tension-decay analytics; compare racquets, strings and completed string jobs. • Personalized string and hybrid recommendations using your playstyle, ratings and eligible retention history. • Tension Advisor with What If scenarios for your equipment, game and conditions. • Tension targets, optional alerts and Smart Detection for likely fresh strings or unusual tension changes. • Playing-hours restring forecasts when enough dependable data is available. • Automatic Apple Health import, detailed playing stats, advanced milestone tools and reminders. • Cost Analytics, cost per playing hour, annual budgets, wishlist and stringer Annual Summary with PDF export. • iCloud sync and PDF/CSV reports, including string-job reports for your stringer. ASK STRING AI COACH Ask about your racquet, tension, strings, playing history, restring timing and costs using your saved data. Questions, answers and racquet data stay on device. Available when the app is set to English, on compatible Apple Intelligence devices with iOS 26 or later, a supported system language and an available on-device model. Some questions require PRO. READY WHEN YOU ARE Check String Status widgets on your Home or Lock Screen. Use Siri, Shortcuts, Spotlight or the Action button to reach supported actions. Import, inspect and restore backups. Measurement audio is processed on device and never saved or uploaded; imported Health session records stay on your iPhone, outside iCloud sync and session exports. Shared summaries may include their totals. Optional analytics require consent. Enjoy smoother measuring, browsing and sharing, more reliable history, forecasts, reports and sync, plus VoiceOver, Dynamic Type and Reduce Motion support. Requires iOS 17 or later. Download free. Learn from every session. Restring with confidence. Terms of Use: https://stringtensionai.com/terms/ Privacy Policy: https://stringtensionai.com/privacy/

About

Goodminton

Features
Read full description

Track every restring. Predict every break. Goodminton Stringly is the string log built for serious BADminton players, drawing on 42 years of playing and 12 years of stringing experience. Log every restring, every break, every tension you tried — and watch the patterns emerge. WHAT YOU CAN DO • Log restrings in seconds — string, tension, date, who strung it • Track break locations and reasons (mid-rally? smash? frame contact?) • See string-life across every racket in your bag • Compare what lasts — by string, tension, racket, or play hours • Restring reminders before your strings die mid-match BUILT FOR Players who restring at least once a month. Stringers who want to give clients a record. Anyone tired of guessing when the string is about to go. Real data that bridges the conversation between players and stringers — so every restring is closer to what you actually want. PRIVACY-FIRST No ads. No tracking across other apps. Your data stays on your device unless you choose to export it. Anonymous usage analytics only — easy to turn off in Settings. ROADMAP Cloud backup, break prediction, shareable racket cards, used-racket exchange, BADminton forum, and a stringer mode — all coming. Tell us what you want at kevinliu217@gmail.com. Made by a 40+ year BADminton player and 12+ year stringer, for every player and stringer. ——— Terms of Use (EULA): https://goodminton.club/terms/ Privacy Policy: https://goodminton.club/privacy/

Screenshots

String Tension AI4 screens
Goodminton4 screens

Verdict

The call

The clearest difference is device support: Goodminton at 3 against String Tension AI's 1. Goodminton also leads on iOS requirement (15.5 vs 17.0). On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. String Tension AI sells 3 in-app purchases, starting at $4.99 per month and Goodminton sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

String Tension AI ships an update every 4 days, Goodminton weekly. The most recent releases landed on October 14, 2026 and October 1, 2026 respectively.

Scorecard2 real differences · 8 level
String Tension AI versus Goodminton: the parameters behind the verdict, then further details
ParameterString Tension AIGoodminton
PriceFreeFree
Rating5.0 (3 ratings) — better—
Positive reviews80.0% of reviews—
Number of ratings3 — better—
Update frequencyEvery 4 days — betterWeekly
AdsNoNo
In-app purchasesYesYes
MonetizationFreemium—
DevicesiPhoneiPhone, iPad, iPod — better
Requires iOS17.015.5 — better
Further details — not scored
Size83 MB274 MB
Age rating4+12+
DeveloperTrader Prosperity LLCKevin Liu

In-app purchases

3 purchases

String Tension AI

Subscriptions2
  • Monthly PRO$4.991 Month
  • Annual PRO$29.991 Year
One-time1
  • Lifetime PRO$69.99
3 purchases

Goodminton

Subscriptions2
  • Goodminton Membership (monthly)7 Days trial$1.991 Month
  • Goodminton Membership (Annual)7 Days trial$16.991 Year
One-time1
  • Lifetime Membership$20.99

Questions

Is String Tension AI free?
String Tension AI is free to download, with in-app purchases available.
Is Goodminton free?
Goodminton is free to download, with in-app purchases available.
Do String Tension AI or Goodminton have ads?
Neither String Tension AI nor Goodminton shows ads.
Which is updated more often, String Tension AI or Goodminton?
String Tension AI ships an update every 4 days, and Goodminton weekly. Most recently, String Tension AI was updated on October 14, 2026 and Goodminton on October 1, 2026.

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