String Master vs String Tension AI
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
String Master
Optimize your tennis game by precisely tracking string tension and durability. Record every restring, analyze string performance, and discover the best setups for your playstyle. Never guess about your strings again.
- Smart Restring logging
- Custom string input
- Smart String Finder
- Restring reminders
- Detailed logs and history
- Hybrid setup support
Read full descriptionHide full description
Stop guessing, start tracking. String Master is the ultimate performance-tracking companion for tennis players who demand the best from their equipment. Whether you are a casual player or a competitive athlete, your string setup dictates your game. String Master helps you record, analyze, and discover the perfect string configurations tailored to your unique playing style. [Major New Updates & Premium Features] • Smart Recommendation Wizard & Normalized Engine Finding your next string is now effortless. Our 3-step recommendation wizard uses lab-tested data (stiffness, spin potential, tension loss, energy return) and scales them using min-max normalization to prescribe the perfect setup matching your game. • Dynamic Activity Calendar & Backdating Visualize your active string health on a color-coded calendar. Log past sessions, backfill older stringing jobs, and edit durations with instant, automatic health percentage recalculations. • Playability & Environmental Logging Go beyond time tracking. Log how your strings feel (Soft, Crisp, Stiff, or Dead Poly), track weather conditions (Sunny, Humid, Cloudy), and record temperatures to understand how environment impacts your tension. • Community Insights & Lifespan Rankings Access real-time community statistics and trends. View the top average string lifespan rankings based on thousands of hours of real player data. (Access is granted to active members with a minimum of 4 hours of logged play over the past 14 days.) • Advanced Racket Specifications Track customized parameters for every racket in your bag. Log weight (g), stiffness (ra), swing weight (kg/cm²), balance point (mm), serial numbers, and custom tuning notes (lead tape, grip details). • Smart Restring & Terminology Polish Log a new job in 3 seconds! Tap "Restring" to clone your previous setup (racket, string, tension). Terminology has been audited and standardized to "History" across 10 languages. • Social Authentication & Data Migration Log in instantly with Google or Apple Sign-In. Seamlessly migrate your entire guest mode racket and stringing history to your permanent account in one click. [Core Features] • Restring Reminders: Set custom notifications (90 days or health below 20%) to prevent arm strain and maintain peak playability. • Hybrid Setup Support: Independently log mains and crosses (different brands, gauges, and tensions). • 10-Language Expert Guides: Tap the info (i) icons to read explanations of string materials and metrics, fully localized in 10 languages (EN, KO, ES, JA, ZH, ZH_Hant, DE, FR, IT, PT).
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.
- 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
Read full descriptionHide 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/
Screenshots
Verdict
The clearest difference is in-app purchases: String Master at none against String Tension AI's 3. String Master also leads on iOS requirement (15.6 vs 17.0). On price, rating, ratings volume and update cadence 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
Both are free to download. String Tension AI sells 3 in-app purchases, starting at $4.99 per month. String Master asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 5.0 for String Master against 5.0 for String Tension AI. Both are backed by a comparable volume of ratings — 7 and 3 respectively.
String Master ships an update weekly, String Tension AI every 4 days. The most recent releases landed on October 1, 2026 and October 14, 2026 respectively.
| Parameter | String Master | String Tension AI |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (7 ratings) | 5.0 (3 ratings) |
| Positive reviews | — | 80.0% of reviews |
| Number of ratings | 7 — better | 3 |
| Update frequency | Weekly | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Freemium |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 15.6 — better | 17.0 |
| Further details — not scored | ||
| Size | 71 MB | 83 MB |
| Age rating | 4+ | 4+ |
| Developer | ORYONG KIM | Trader Prosperity LLC |
Customer experience
String Master
String Tension AI
In-app purchases
String Master
No in-app purchases
String Tension AI
- Monthly PRO$4.991 Month
- Annual PRO$29.991 Year
- Lifetime PRO$69.99
Questions
Is String Master free?
Is String Tension AI free?
Which has better reviews, String Master or String Tension AI?
Do String Master or String Tension AI have ads?
Which is updated more often, String Master or String Tension AI?
Other comparisons















