Flying Ruler Pro 4+

For the accurate measurements


    • 4.1 • 184 Ratings
    • $0.59



Available at a 80% discount for a limited time only!

The Flying Ruler app allows you to measure in the most original way: by just moving your device from one point to another.

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!


Editor's Choice — 148Apps

*** Only on iOS ***

To try this technology for free you can install the app "Goniometer Plus". This free app measures the angle as you move the device.


"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" —

"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 ***

Flying Ruler is a tape measure, ruler, protractor and a goniometer (angle-measurer). It is four 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.

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 ruler in another. You can not only measure an object but also the distance between two walls. You use the same methods to measure angles as the app allows you to measure angles both on a surface area and between surfaces through space.

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.


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 goniometer (angle measurer).


What’s New

Version 6.0

- increased accuracy on some devices
- improved user interface
- optimized for iOS 17
- advanced calibration (when necessary)
- support for all new devices, including iPhone 15 (Plus / Pro / Pro Max)
- other minor alterations and improvements

While the program is running, you can listen to music or podcasts in the background. However, during the measurement, all sounds from the built-in speaker will be muted to increase accuracy.

Ratings and Reviews

4.1 out of 5
184 Ratings

184 Ratings

Nariosan ,

The one to get!

Out of 6 measurement apps I downloaded this is the only one I kept. Here's why
#1 it works. It actually measures any distances pretty accurately.
#2 ease of use/ versatile:
Drop phone at starting point and press button, pick it up when it turns green and drop phone off at end point. Whether inches or feet away. It doesn't matter.
#3 truth in advertising. All others say free and then you find you can't use them without paying money. This one says $1.99 up front. No tricks.
#4 cheapest and most accurate. The others use things like photos and they are just not as accurate as this one.
Improvements? Of course I'd like it better if it was free. But you get your money's worth. What measurement tape cost less and goes longer? And you always have it with you.
PS: the calibration method is so simple it may confuse you. Just drop phone on a flat surface as shown/ oriented on drawing and it automatically detects it and places a check mark. Repeat till all 6 drawings have a check mark.
Just pay attention to the drawing: which way is the button? (up, down, face down etc. )

Docj ,

Fantastic technology

I was looking all over the App Store for some measuring app to measure between walls and distances. The only thing out there were stupid apps were you had to hold your finger down and slide the phone hoping your fingers don't slide off the screen. This app is using technology to basically lift the phone and put it down from one point to another and the accuracy is extremely good but of course it will never equal a measuring tape. I can imagine using this while I'm out and about and needing to measure something in the store

Iconic730 ,

Great and really accurate app!!

This app does a phenomenal job of taking precise measurements. It's not 100% (with a case) so it can't replace a ruler for small measurements but it's pretty close (off by maybe a 1/16th")! It is by far the most superior app I have found on the market though!!

App Privacy

The developer, ALEXEY BRILEV, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Linked to You

The following data may be collected and linked to your identity:

  • Identifiers

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Usage Data
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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