Strobe tachometer (RPM meter) vs Vsensor
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Strobe tachometer (RPM meter)
Measure rotational speeds of objects using your phone's flashlight, laser, or magnetic sensor. Detect precise RPMs with adjustable flicker frequencies and a wide measurement range. Ideal for analyzing fan speeds, engine RPMs, and more.
- Strobe tachometer function
- Laser tachometer mode
- Magnetic tachometer mode
- Adjustable flicker frequency
- RPM and Hz display
- High precision measurement
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STROBE TACHOMETER When the flicker frequency of light coincides with the speed of any object, such as a fan, the rotating fan may appear to be stationary. Changing the frequency of the flicker of light may help detect the rotation speed. You may easily use the flicker frequency control buttons to quickly assign the flicker frequency with an accuracy of 0.0001 Hz (0.01 RPM): • Up to 1000 Hz (60 000 RPM) for a connected flashlight (see the video on YouTube: https://youtu.be/iq6Xiums05o). • Up to 100 Hz (6000 RPM) for the iPhone flashlight. IF THE SPEED IS MORE THAN UPPER LIMIT, YOU MAY STILL DETERMINE THE SPEED BY FIRST MAKING MEASUREMENTS WITH A LOWER FLICKER FREQUENCY AND THEN MAKING A SIMPLE CALCULATION (AS EXPLAINED IN THE APPENDIX). To change the frequency, you should simply press and hold the button. In the app settings, you can adjust the speed at which the flash rate changes when you press and hold the button. The flicker frequency can be displayed either in Hz or RPM. The image you see will be sharper in lower external light. After a long period of usage, in case of overheating, the iPhone flashlight turns off automatically. LASER TACHOMETER • Measurement range from 0.3 Hz (18 RPM) to 1000 Hz (60 000 RPM). • Step 0.01-0.0001 Hz (1-0.01 RPM). • Update time 1 sec. • 5 mW laser power required. MAGNETIC TACHOMETER This tachometer operates by measuring the magnetic field from a spinning magnet. The magnetic field is measured by the iPhone's magnetometer. The magnetic tachometer is best suited for measuring low rotation speeds (from 6 revolutions per minute). It can also be used for measuring medium rotation speeds (up to 2,700 RPM), but at such speeds there is a risk of spontaneous tearing away of the magnet and strong vibration due to center-of-gravity shift. • Measurement range from 0.1 Hz (6 RPM) to 45 Hz (2,700 RPM). • Step 0.2-2 %. • Update time 2-5 sec.
Vsensor
This utility app displays environmental data like PAR, CO2, and CO concentrations directly on your phone. It requires compatible external meters to function.
- Displays PAR data
- Shows CO2 concentration
- Reads CO concentration
- Works with external meters
- Professional tool
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To show the datas of PAR, CO₂ concentration and CO concentration in phone by working with corresponding meters.
Screenshots
Verdict
The clearest difference is rating: Strobe tachometer (RPM meter) at 4.3 against Vsensor's 3.0. Strobe tachometer (RPM meter) also leads on ratings volume (83 vs 8) and review sentiment (69% vs 60%). Vsensor's advantage is in-app purchases (none vs 2) and update cadence (every 3 weeks vs every 4 months). On price, 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
Both are free to download. Strobe tachometer (RPM meter) sells 2 one-off in-app purchases. Vsensor asks for nothing beyond the download.
Strobe tachometer (RPM meter) holds the better App Store score, 4.3 against 3.0. That said, the two scores are not equally well evidenced: Strobe tachometer (RPM meter) has 83 ratings behind it against 8, so its average is the more settled of the two. Written reviews point the same way: 69% of Strobe tachometer (RPM meter)'s written reviews are positive against 60% of Vsensor's.
Strobe tachometer (RPM meter) ships an update every 4 months, Vsensor every 3 weeks. The most recent releases landed on September 9, 2026 and August 18, 2026 respectively.
| Parameter | Strobe tachometer (RPM meter) | Vsensor |
|---|---|---|
| Price | Free | Free |
| Rating | 4.3 (83 ratings) — better | 3.0 (8 ratings) |
| Positive reviews | 69.0% of reviews — better | 60.0% of reviews |
| Number of ratings | 83 — better | 8 |
| Update frequency | Every 4 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPod | iPhone, iPod |
| Requires iOS | 15.6 | 15.1 — better |
| Further details — not scored | ||
| Size | 16 MB | 70 MB |
| Age rating | 4+ | 4+ |
| Developer | Dmitriy Kharutskiy | 健成 李 |
Customer experience
Strobe tachometer (RPM meter)
Vsensor
In-app purchases
Strobe tachometer (RPM meter)
- Full version of the stroboscopic tachometer$2.99
- Laser Tachometer and Magnetic$2.99
Vsensor
No in-app purchases
Questions
Is Strobe tachometer (RPM meter) free?
Is Vsensor free?
Which has better reviews, Strobe tachometer (RPM meter) or Vsensor?
Do Strobe tachometer (RPM meter) or Vsensor have ads?
Which is updated more often, Strobe tachometer (RPM meter) or Vsensor?
Other comparisons
