# Video tachometer — Strobe light effect, RPM meter

> Measures rotational speed using strobe effect and slow-motion video analysis. (iPhone/iPad app by Dmitriy Kharutskiy.)

- Source: https://appshunter.io/ios/app/video-tachometer/id1492583587 (this page in markdown: same URL + `.md`)
- Developer: [Dmitriy Kharutskiy](https://appshunter.io/developer/817385891)
- Category: Utilities, Education
- Price: Free with in-app purchases
- Rating: 4.60/5 from 84 App Store ratings · 52 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.6 · 5 MB
- Languages: Dutch, German (Germany), Russian, Swedish, European Spanish, American English, Italian, Japanese, Czech, Brazilian Portuguese and 1 more
- Released: 2019-12-28
- Data updated: 2026-08-25
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/video-tachometer/id1492583587/reviews.md

## What is Video tachometer?

When the frame rate of a video matches the speed of a particular part, the effect is the same as using a strobe light. In the video, that part freezes.

Since the frame rate of a video can be adjusted, this effect can be used to determine the rotational speed of a part.

The smartphone must support slow-motion video recording (filming at a high frame rate). This is the case for all smartphones starting with iPhone 5S. The range is as follows:

• 0.5—240 Hz (30—14400 RPM), for all phones from iPhone 6 onward
• 0.5—120 Hz (30—7200 RPM), for iPhone 5S

THE HERTZ (Hz) VALUE IS MORE ACCURATE THAN THE REVOLUTIONS PER MINUTE (RPM) VALUE, SINCE REVOLUTIONS PER MINUTE ARE CALCULATED FROM HERTZ AND ROUNDING IS DONE.

To get a clear image, good lighting is important. The clarity of the image is controlled by the exposure of the video (exposure time and light sensitivity (ISO)). If the exposure time is reduced, the image will increase in clarity, but brightness will lower. To increase the brightness, you need to raise the camera's light sensitivity (ISO), but then the amount of noise increases. You also need to manually adjust the focus of the camera.

The app can record video. The video format depends on the selected format in the app settings. If your iPhone supports 4K video format (3840x2160), then you can record 4K video at the frame rate supported by your iPhone. Text with important information is added to the frames of the recorded video: the selected frame rate, exposure duration, ISO, time stamp, time difference between the current and previous frames (Tcurr. − Tprev.), the sequence number of the frame in the recorded video. If you want any other information to be added, then let me know. 

You can choose to add only part of this information, and you can choose a different text color. You also have the option of not adding any information. You can change the information that is added and the color of the text while recording a video. At high frame rates, frames that do not have time to be processed may be discarded. This does not affect subsequent frames and can be controlled using the time difference between the current frame and the previous frame (Tcurr. − Tprev.). Dropping frames affects the video frame rate displayed in the "Photos" app. But the time interval between frames that were taken one after another and were not discarded will correspond to the selected frame rate. Frames may be dropped even when shooting slow motion video using the "Camera" app. You can check this by looking at the frame rate for slow motion video in the "Photos" app.

Video containing the app's interface can be captured using the iOS "Screen Recording" function.

The app can take a photo with the measurement result, date, and time written on the photo. The exposure time and ISO settings will be saved in the photo's metadata. To take a photo that shows the app interface, tap the "Pause" button and take a screenshot.

It is possible to choose a video format that has the best quality, but has a significantly lower maximum frame rate. The difference between the formats is clearly visible only when using the digital zoom. Also, when using a format with better quality, the Rolling Shutter effect is stronger. Therefore, the best quality format can be used at speeds less than about 2000 rpm.

You can turn on hints for easier observation of changes in rotation speed. Hints show how to change the frame rate (decrease or increase) depending on the direction of rotation of the mark. The hints are selected manually, but then you do not need to remember this information. The hints are relevant for frequencies close to the rotation frequency. If the direction of rotation of the impeller is known, hints can be selected in advance. The arrow showing the direction of rotation of the impeller must correspond to the "+" button.

The video tachometer measures the rotational speed in exactly the same way a stroboscopic tachometer would.

## Key features

- Strobe light effect simulation
- Rotational speed measurement (RPM/Hz)
- Slow-motion video recording
- Customizable text overlays on video
- Adjustable frame rate and exposure
- Records 4K video (if supported)

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Full version | $2.99 | one-time |


## Recent user reviews (10 of 52)

All indexed reviews: https://appshunter.io/ios/app/video-tachometer/id1492583587/reviews.md

### 5/5 — Works

*2026-07-18*

Wanted to check RPM.   I knew what it should be.   1125.   I set this app to 1130 and my mark almost stopped, 1140 it spun backwards slowly.   Just right.   Very cool.

**Developer response:** Thanks for your feedback! In the full version, you can select the frame rate for 1125 RPM. In the free version, the frame rate selection accuracy is ±10 RPM (or ±0.1 Hz), in the paid version, the frame rate selection accuracy is ±1 RPM (or ±0.01 Hz).

### 5/5 — It works, just need

*2026-07-15*

The app is very good, it takes a few tries to get the right settings to understand the different options and how they can be used, nothing impossible to do, if you try the app different settings you will find them very useful, after a few tries you will find the settings that are the best for you to use and understand. Excellent app just practice to master the settings.

### 5/5 — Полезное приложение.

*2026-05-21*

Понадобилось измерить обороты bldc мотора от машины, все получилось отлично.
Понятное и удобное приложение.

### 5/5 — Super Useful

*2025-04-26*

I don't own a lot of tools (being a college student), so when I wanted to measure the RPM of my Lego motor to determine its torque, I was stuck. Looking on the AppStore was a last, desperate measure, but man, I'm glad I did. The free version of the app work beautifully and offers great control and features. And, the +-10RPM is not a huge deal. Overall, would absolutely recommend. Many thanks to the developer for providing this tool for free!

### 5/5 — Классный инструмент

*2025-04-21*

Отличное приложение. Сегодня собирал стенд, в котором использовался частотник. С помощью приложения получилось выставить нужные мне обороты электродвигателя. Так же проверил правильно ли я рассчитал шкивы. Однозначно рекомендую всем кто занимается ремонтом и диагностикой различных механизмов. Мощный карманный инструмент.

### 2/5 — It’s ok

*2025-04-12, version 2.1.1*

I  think that people ar trying to get rich on getting people to buy this I deleted it that is all I have to say!😬😑🙄

### 1/5 — Ripoff

*2025-03-25, version 2.1.1*

This app is charging my credit card and I have deleted the app. This is a ripoff and a scam be careful!

### 2/5 — Very little usefulness in the free version

*2024-11-12, version 2.1.1*

Far too much is only in the paid version.  Uninstalled within five minutes of installing.

### 5/5 — Clever and useful

*2024-10-08*

I found this app to be incredibly useful. I didn’t trust the tachometer on my boat, and this app worked like a charm in confirming it. It’s beautifully done.

I didn’t quite understand why I needed the 2X and divided by two buttons, but it becomes clear after you’ve used it for a bit, and that you need to find the maximum RPM value that works otherwise you might be looking at halftime or quarter time or eighth time Etc., but two dollars it’s a steal.

Clever Developers should be rewarded. Well done!

### 5/5 — Fantastic

*2024-08-25, version 2.1*

Great app!

## Frequently asked questions about Video tachometer

### What does this app do?

This application utilizes the slow-motion video recording capabilities of your smartphone to create a strobe light effect. This effect allows you to visually freeze parts of a rotating object, enabling the measurement of its rotational speed in Hertz (Hz) or Revolutions Per Minute (RPM).

### How accurate is the speed measurement?

The app provides measurements in both Hertz (Hz) and Revolutions Per Minute (RPM). The Hertz value is considered more accurate as RPM is calculated from Hertz and involves rounding. The accuracy also depends on factors like good lighting, clear video, and manual focus adjustment.

### What are the system requirements?

Your smartphone must support slow-motion video recording, which is standard on iPhones starting with the iPhone 5S. Specific ranges for measurement are available for different iPhone models, with newer models supporting higher frame rates and RPM ranges.

### Can I record videos with measurement data?

Yes, the app can record video and add text with important information directly to the frames. You can choose to include the selected frame rate, exposure duration, ISO, timestamp, and time difference between frames, with options to customize the text color or omit it entirely.

### Is this app free to use?

The application is available for free with the option for in-app purchases. This suggests that while core functionality may be free, certain advanced features or enhancements might require a purchase.

## Version history (last 5 releases)

### 2.1.10 — 2026-08-22

• The phase shift of a moving object in an image when the image is made still. Touch and hold.

### 2.1.9 — 2026-08-15

• A photo with the result of the measurement written on the photo.

### 2.1.8 — 2026-07-07

• Full support for iPad.

### 2.1.6 — 2026-04-15

• Bug fixes.

### 2.1.5 — 2026-02-15

• Bug fixes.

## Apps similar to Video tachometer

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Strobe tachometer (RPM meter)](https://appshunter.io/ios/app/strobe-tachometer-rpm-meter/id831460940) | 4.3 (83) | Free | Utilities |
| [Camera RPM Meter - StrobeLight](https://appshunter.io/ios/app/camera-rpm-meter-strobelight/id1583247436) | 2.3 (33) | Free | Utilities |
| [Flashlight for iPhone + iPad](https://appshunter.io/ios/app/flashlight-for-iphone-plus-ipad/id388838723) | 4.5 (133,632) | Free | Utilities |
| [Flashlight Ⓞ](https://appshunter.io/ios/app/flashlight/id381471023) | 4.5 (30,367) | Free | Utilities |
| [Best Flash Light - Flashlight](https://appshunter.io/ios/app/best-flash-light-flashlight/id429177928) | 4.7 (46,181) | Free | Utilities |
| [Flashlight ○](https://appshunter.io/ios/app/flashlight/id384365348) | 4.7 (28,534) | Free | Utilities |

## More apps by Dmitriy Kharutskiy

- [Vibration analysis](https://appshunter.io/ios/app/vibration-analysis/id817385888)
- [Strobe tachometer (RPM meter)](https://appshunter.io/ios/app/strobe-tachometer-rpm-meter/id831460940)
- [Talking Speedometer](https://appshunter.io/ios/app/talking-speedometer/id883280026)
- [Speedometer, Speed Limit Alert](https://appshunter.io/ios/app/speedometer-speed-limit-alert/id899935974)
- [DIY Anemometer (Wind Meter)](https://appshunter.io/ios/app/diy-anemometer-wind-meter/id1313709233)
- [DIY Metal Detector (Au,Ag,Fe)](https://appshunter.io/ios/app/diy-metal-detector-auagfe/id1404284012)

All apps by Dmitriy Kharutskiy: https://appshunter.io/developer/817385891

## Related topics

[rpm strobe](https://appshunter.io/ios/topics/rpm-strobe) · [tachometer digital](https://appshunter.io/ios/topics/tachometer-digital) · [camera rpm meter](https://appshunter.io/ios/topics/camera-rpm-meter) · [tachometer rpm](https://appshunter.io/ios/topics/tachometer-rpm) · [strobe tachometer](https://appshunter.io/ios/topics/strobe-tachometer) · [strobe light tachometer](https://appshunter.io/ios/topics/strobe-light-tachometer) · [rpm meter](https://appshunter.io/ios/topics/rpm-meter) · [rpm reader](https://appshunter.io/ios/topics/rpm-reader) · [rpm speed](https://appshunter.io/ios/topics/rpm-speed) · [tachometer acoustic](https://appshunter.io/ios/topics/tachometer-acoustic)

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-25.*