Comparison

Flying Ruler vs Ring Sizer Tool

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

Head to head
About

Flying Ruler

Measure distances and angles using your device's sensors. This app functions as a ruler, tape measure, rangefinder, protractor, and 3D angle finder, offering a quick and accurate way to take measurements in various conditions.

Highlights
  • Measure distance by moving device
  • Ruler, tape measure, rangefinder
  • Protractor and 3D angle finder
  • Inertial navigational system technology
  • Adjustable units (inches/cm)
  • Save measurements with photos
  • Avoid obstacles during measurement
Read full description

The Flying Ruler app allows you to measure in the most original way: by just moving your device from one point to another. Flying Ruler is a ruler, tape measure, rangefinder, protractor and a 3D angle finder. It is five devices in one app, providing you with the quickest way to measure a distance or an angle. The secret of the program is that it is based on the principles of the inertial navigational system (INS): the position of the device is determined with the help of the accelerometer and the gyroscope. Measurements take place extremely quickly and at the same time they are quite accurate. We are constantly improving our computational algorithm for more than 11 years! To try this technology for free you can install the app "Digital Angle Finder: 3D Meter". This free app measures the angle as you move the device. AWARDS: Editor's Choice — 148Apps www.148apps.com/reviews/flying-ruler-review PRESS ABOUT US: "I was impressed with Flying Ruler’s accuracy. It works quickly and effectively", "It’s the perfect addition to anyone’s app collection" — 148apps 4.5 / 5 (MUST HAVE) "This thing is awesome" — brettterpstra.com "I literally said “wow!” when I first used this app and I think it’s a truly impressive marvel of mobile technology", "The Flying Ruler Rules" — AppPicker (Cons: there is nothing negative to say about this app) *** Measure distance with good precision, no matter the lighting or conditions *** The app has different modes so you can choose which mode is better and easier to use on each occasion. You can measure with the body of the device in one mode or with a virtual tape measure in another. You can not only measure an object but also the distance between two walls (rangefinder mode). You use the same methods to measure angles as the app allows you to measure angles both on a surface area (protractor mode) and between surfaces through space (3D angle finder mode). You can choose either inches or centimeters. The maximum distance is only limited by the value of the indicator which consists of 999 ft for the imperial system and 99 m for the metric system. When measuring, you can avoid obstacles and therefore you can measure anything. Flying Ruler is suitable for measuring not only large, but also very small distances with the accuracy of a standard ruler. The app also allows you to save a measurement by taking a photograph of the measurement and mark the place that was measured. Don’t forget to show your friends and colleagues how the app works – believe us, they will be impressed. ACCURACY OF MEASUREMENT: We took 100 consecutive measurements and got these results: On iPhone 13: • Mean squared error - 0.14% • Maximum inaccuracy - 0.4% On iPhone 7: • Mean squared error - 0.15% • Maximum inaccuracy - 0.4% On iPhone 6s: • Mean squared error - 0.28% • Maximum inaccuracy - 1.1% The accuracy of measurements depends on the device, however the error rarely exceeds 1.5%. You can always increase accuracy by making a series of measurements. If you make a series of measurements, the degree of error is usually 0.3% or less. Angles can be measured with the app to an accuracy of one degree so the app can easily take the place of a protractor or a angle finder. WEBSITE: www.flying-ruler.com

About

Ring Sizer Tool

Accurately measure your finger size or compare existing rings to find the perfect fit. This tool simplifies ring sizing for confident online purchases and jewelry selection.

Highlights
  • Finger measurement without a ring
  • Ring comparison for sizing
  • Intuitive and simple interface
  • Accurate sizing for online shopping
  • Suitable for buyers and jewelers
Features
Read full description

Welcome to Ring Sizer Tool: Your key to precision in ring sizing. Eliminate the guesswork and convoluted methods of old. With Ring Sizer Tool, you achieve a spot-on fit with ease. Why Choose Ring Sizer Tool: No Ring? No Problem: If you lack a ring for comparison, we've got you. Ring Sizer Tool offers spot-on finger measurements, ensuring an impeccable fit each occasion. Intuitive Design: Ring Sizer Tool interface is both simple and inviting. New to digital tools or a tech enthusiast, our layout is made for you. Everyone's Perfect Companion: From the occasional ring buyer to expert jewelers, Ring Sizer Tool fits the bill. It's your go-to for confident online ring selections. Elevate your jewelry game with Ring Sizer Tool. Enjoy online shopping with newfound assurance, always nailing that perfect size. Eager for hassle-free sizing? Step into the world of Ring Sizers and attain accurate results in a flash. Celebrate the end of sizing mishaps and the dawn of tailored perfection! To access all features, content, and functionality you can subscribe to an annual auto-renewable subscription. This is a recurring transaction that will be charged to your iTunes Account at confirmation of purchase and will automatically renew unless you cancel it at least 24 hours before the end of your subscription. Renewals will be charged the same cost within 24 hours prior to the end of the current period. You can manage your subscriptions and auto-renewal can be turned off by going to your iTunes Account Settings after purchase. Privacy Policy: https://appcano.io/privacy Terms of Use: https://appcano.io/terms

Screenshots

Flying Ruler4 screens
Ring Sizer Tool3 screens

Verdict

The call

The clearest difference is price: Ring Sizer Tool at Free against Flying Ruler's $1.99. Ring Sizer Tool also leads on rating (4.7 vs 4.1) and ratings volume (604 vs 187). Flying Ruler's advantage is in-app purchases (none vs 1) and review sentiment (86% vs 70%). On update cadence, ads, device support and iOS requirement 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

Ring Sizer Tool is free to download; Flying Ruler costs $1.99 up front. Ring Sizer Tool sells 1 in-app purchase, starting at $19.99 per year. Flying Ruler asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Ring Sizer Tool holds the better App Store score, 4.7 against 4.1. Both are backed by a comparable volume of ratings — 187 and 604 respectively. Written reviews complicate that: 86% of Flying Ruler's written reviews are positive against 70% of Ring Sizer Tool's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Flying Ruler ships an update every 2 months, Ring Sizer Tool every 5 weeks. The most recent releases landed on September 23, 2026 and September 21, 2026 respectively.

Scorecard6 real differences · 4 level
Flying Ruler versus Ring Sizer Tool: the parameters behind the verdict, then further details
ParameterFlying RulerRing Sizer Tool
Price$1.99Free — better
Rating4.1 (187 ratings)4.7 (604 ratings) — better
Positive reviews86.3% of reviews — better70.0% of reviews
Number of ratings187604 — better
Update frequencyEvery 2 monthsEvery 5 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaid — betterSubscription
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.015.0
Further details — not scored
Size78 MB68 MB
Age rating4+4+
DeveloperALEXEY BRILEVAppcano LLC

Customer experience

Flying Ruler

All ratings187 ratings
Positive81.3%
Neutral4.3%
Negative14.4%
Written reviews461 reviews
Positive86.3%
Neutral4.6%
Negative9.1%

Ring Sizer Tool

All ratings604 ratings
Positive93.4%
Neutral2.8%
Negative3.8%
Written reviews20 reviews
Positive70.0%
Neutral0.0%
Negative30.0%

User reviews

Flying Ruler

From 187 App Store ratings

What we love

  • 👍 Easy to use
  • 🚀 Convenient for quick measurements
  • 💡 Clever use of phone sensors
  • ⭐ Accurate for most use cases
  • 🎨 Visually appealing interface

Room to improve

  • 🐛 Inconsistent measurement accuracy
  • 📏 Not as precise as a physical ruler
  • ⚠️ Requires multiple measurements for reliable results
  • 🤔 Confusing calibration process

Ring Sizer Tool

From 604 App Store ratings

What we love

  • 👍 Easy to use
  • ✅ Accurate sizing
  • 💰 Free to use
  • 📱 Works with newer iPhones
  • 💡 Better than paper methods

Room to improve

  • ❌ Inaccurate finger sizing
  • ❌ Wildly wrong estimates
  • ❌ Doesn't work for some users

Bugs and requests

Flying Ruler

Reported bugs

3 issues
  • Measurements vary wildly between attempts
  • Calibration process fails to complete
  • App crashes when used with certain phone cases

Requested features

4 requests
  • Add imperial unit support
  • Integrate with smart home devices
  • Provide more advanced measurement tools
  • Improve accuracy for smaller distances

Ring Sizer Tool

Requested features

1 request
  • Dynamically update values as slider adjusts

In-app purchases

None

Flying Ruler

No in-app purchases

1 purchases

Ring Sizer Tool

Subscriptions1
  • Ring Sizer Annual3 Days trial$19.991 Year

Questions

Is Flying Ruler free?
Flying Ruler costs $1.99, with no in-app purchases.
Is Ring Sizer Tool free?
Ring Sizer Tool is free to download, with in-app purchases available.
Which has better reviews, Flying Ruler or Ring Sizer Tool?
Ring Sizer Tool is rated higher. Flying Ruler averages 4.1 out of 5 from 187 ratings, while Ring Sizer Tool averages 4.7 from 604 ratings.
Do Flying Ruler or Ring Sizer Tool have ads?
Neither Flying Ruler nor Ring Sizer Tool shows ads.
Which is updated more often, Flying Ruler or Ring Sizer Tool?
Flying Ruler ships an update every 2 months, and Ring Sizer Tool every 5 weeks. Most recently, Flying Ruler was updated on September 23, 2026 and Ring Sizer Tool on September 21, 2026.

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