Comparison

SwingTool vs String Master

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

Head to head
About

SwingTool

Easily measure the swing weight of sports equipment like tennis racquets, golf clubs, and baseball bats. This tool simplifies a complex measurement, allowing you to understand how your equipment feels when you swing it.

Highlights
  • Measures swing weight of various sports equipment
  • Calculates swing weight at any chosen point
  • Independent swing point and hanging point selection
  • Faster and more accurate than traditional methods
  • Measures pendulum swing time with 0.01s accuracy
  • Performs MOI-matching for dynamic swing weight
Read full description

SwingTool can quickly and easily measure the swing weight of tennis racquets, golf clubs, baseball bats etc. Swing weight is the most important parameter when deciding how a racquet, club or bat feels when you swing it. Unfortunately measuring swing weight has been fairly complicated, until now. With SwingTool it is enough to just hang your equipment and let it swing like a pendulum. Place the iPhone close to the swinging end and it will automatically display the swing weight. Characteristics - Can be used for all types equipment - Choose any point to calculate the swing weight at - Choose any point to hang the equipment at (independent of the swing point) - Faster and more accurate than the traditional way to measure swing weight - Can be used to measure the swing time of any pendulum with 0.01 s accuracy A demo video is available at appmaker.se/swingTool To golfers: With this app you do MOI-matching i.e. it measures the real dynamic swing weight (moment of inertia). Not the static Lorythmic balance point (D9, C4 etc) that sometimes is called swing weight.

About

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.

Highlights
  • Smart Restring logging
  • Custom string input
  • Smart String Finder
  • Restring reminders
  • Detailed logs and history
  • Hybrid setup support
Features
Read 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).

Screenshots

SwingTool3 screens
String Master4 screens

Verdict

The call

The clearest difference is price: String Master at Free against SwingTool's $1.99. String Master also leads on rating (5.0 vs 4.2) and update cadence (weekly vs every 7 months). SwingTool's advantage is iOS requirement (8.0 vs 15.6). On ratings volume, ads, in-app purchases and device support 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

String Master is free to download; SwingTool costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

String Master holds the better App Store score, 5.0 against 4.2. Both are backed by a comparable volume of ratings — 17 and 7 respectively.

UpkeepUpdate frequency

SwingTool ships an update every 7 months, String Master weekly. Both last shipped on October 17, 2026.

Scorecard5 real differences · 5 level
SwingTool versus String Master: the parameters behind the verdict, then further details
ParameterSwingToolString Master
Price$1.99Free — better
Rating4.2 (17 ratings)5.0 (7 ratings) — better
Positive reviews84.6% of reviews—
Number of ratings17 — better7
Update frequencyEvery 7 monthsWeekly — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidFree — better
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS8.0 — better15.6
Further details — not scored
Size2 MB71 MB
Age rating4+4+
DeveloperSten KaiserORYONG KIM

Customer experience

SwingTool

All ratings17 ratings
Positive76.5%
Neutral11.8%
Negative11.8%
Written reviews26 reviews
Positive84.6%
Neutral3.8%
Negative11.5%

String Master

All ratings7 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

SwingTool

No in-app purchases

None

String Master

No in-app purchases

Questions

Is SwingTool free?
SwingTool costs $1.99, with no in-app purchases.
Is String Master free?
String Master is free to download, with no in-app purchases.
Which has better reviews, SwingTool or String Master?
String Master is rated higher. SwingTool averages 4.2 out of 5 from 17 ratings, while String Master averages 5.0 from 7 ratings.
Do SwingTool or String Master have ads?
Neither SwingTool nor String Master shows ads.
Which is updated more often, SwingTool or String Master?
SwingTool ships an update every 7 months, and String Master weekly. Most recently, SwingTool was updated on October 17, 2026 and String Master on October 17, 2026.

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