Flying Ruler vs Ring Sizing
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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
Ring Sizing
Accurately measure ring sizes using your phone's screen. Determine diameter, circumference, and convert between international sizing systems. Ideal for jewelers and shoppers needing precise measurements.
- Measure ring diameter on screen
- Determine circumference in mm/inches
- Pacher method calculation
- International size conversion (EU, US, UK, JP)
- Precise slider for measurement
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Ring Size Find the perfect ring size quickly and accurately. Ring Size makes it easy to determine the correct ring size for yourself or someone special. Simply place a ring directly on your iPhone or iPad screen and adjust the on-screen circle with the slider until it perfectly matches the inside diameter of your ring. The app instantly calculates all important measurements and converts them into the most common international ring size standards. Features • Measure ring size directly on your screen • Precise diameter adjustment with an easy slider • Calculate ring circumference in millimeters and inches • Display the inside diameter • International ring size standards: * European sizes * US sizes * UK sizes * Japanese sizes • Supports the Pacher sizing method • Fast, accurate and easy to use • Perfect for jewelry shopping, jewelers and goldsmiths Whether you're buying an engagement ring, wedding band or fashion jewelry, Ring Size helps you find the perfect fit and avoid costly mistakes. An essential tool for online jewelry shopping and professional use.
Screenshots
Verdict
The clearest difference is price: Ring Sizing at Free against Flying Ruler's $1.99. Flying Ruler's advantage is rating (4.1 vs 1.0) and ratings volume (186 vs 1). On 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
Ring Sizing is free to download; Flying Ruler costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Flying Ruler holds the better App Store score, 4.1 against 1.0. That said, the two scores are not equally well evidenced: Flying Ruler has 186 ratings behind it against 1, so its average is the more settled of the two.
Flying Ruler ships an update every 2 months, Ring Sizing every 10 months. The most recent releases landed on October 29, 2026 and October 12, 2026 respectively.
| Parameter | Flying Ruler | Ring Sizing |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 4.1 (186 ratings) — better | 1.0 (1 ratings) |
| Positive reviews | 86.3% of reviews | — |
| Number of ratings | 186 — better | 1 |
| Update frequency | Every 2 months — better | Every 10 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 78 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | ALEXEY BRILEV | Gerhard Lentschik |
Customer experience
Flying Ruler
Ring Sizing
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 Sizing
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Flying Ruler
No in-app purchases
Ring Sizing
No in-app purchases
Questions
Is Flying Ruler free?
Is Ring Sizing free?
Which has better reviews, Flying Ruler or Ring Sizing?
Do Flying Ruler or Ring Sizing have ads?
Which is updated more often, Flying Ruler or Ring Sizing?
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