Comparison

Video tachometer vs SUNNYSKY

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

Head to head
About

Video tachometer

This app uses slow-motion video to create a strobe light effect, allowing you to measure rotational speeds. It records video with detailed information like frame rate and exposure, and offers customizable text overlays.

Highlights
  • 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)
Read full description

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.

About

SUNNYSKY

Features
Read full description

SUNNYSKY establishes a connection through the Bluetooth of the mobile phone and the Bluetooth of the ESC, so as to realize the functions of adjusting the parameters of the ESC, viewing the data, and upgrading the firmware.

Screenshots

Video tachometer4 screens
SUNNYSKY4 screens

Verdict

The call

The clearest difference is in-app purchases: SUNNYSKY at none against Video tachometer's 1. SUNNYSKY also leads on update cadence (every 9 days vs every 3 months) and iOS requirement (12.4 vs 15.6). On price, ads 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

Both are free to download. Video tachometer sells 1 one-off in-app purchase. SUNNYSKY asks for nothing beyond the download.

UpkeepUpdate frequency

Video tachometer ships an update every 3 months, SUNNYSKY every 9 days. The most recent releases landed on September 10, 2026 and February 26, 2026 respectively.

Scorecard3 real differences · 7 level
Video tachometer versus SUNNYSKY: the parameters behind the verdict, then further details
ParameterVideo tachometerSUNNYSKY
PriceFreeFree
Rating4.6 (84 ratings) — better
Positive reviews84.6% of reviews
Number of ratings84 — better
Update frequencyEvery 3 monthsEvery 9 days — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.612.4 — better
Further details — not scored
Size5 MB5 MB
Age rating4+4+
DeveloperDmitriy Kharutskiy翔 任

In-app purchases

1 purchases

Video tachometer

One-time1
  • Full version$2.99
None

SUNNYSKY

No in-app purchases

Questions

Is Video tachometer free?
Video tachometer is free to download, with in-app purchases available.
Is SUNNYSKY free?
SUNNYSKY is free to download, with no in-app purchases.
Do Video tachometer or SUNNYSKY have ads?
Neither Video tachometer nor SUNNYSKY shows ads.
Which is updated more often, Video tachometer or SUNNYSKY?
Video tachometer ships an update every 3 months, and SUNNYSKY every 9 days. Most recently, Video tachometer was updated on September 10, 2026 and SUNNYSKY on February 26, 2026.

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