Comparison

Strobe tachometer (RPM meter) vs FunDecider

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

Head to head
About

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.

Highlights
  • Strobe tachometer function
  • Laser tachometer mode
  • Magnetic tachometer mode
  • Adjustable flicker frequency
  • RPM and Hz display
  • High precision measurement
Read full description

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.

About

FunDecider

Features
Read full description

Introducing FunDecider, the app designed to make decision-making fun and easy! Simply input your question, list your options, and spin the wheel for a random answer. With FunDecider, quick decision-making has never been more convenient! We understand the challenges of making decisions. Steak or hamburger? Green or blue? One activity or another? That's why we developed the FunDecider app - specifically designed for you! Check out some of the app's features: - Customize your own wheel - Make quick decisions with a single click - Utilize pre-made decision templates - Choose from a variety of color themes - Enjoy a fun prank mode For Apple subscribers, payment will be charged to your App Store account upon confirmation of purchase. Unless auto-renew is turned off at least 24 hours before the end of the current period, your subscription will automatically renew. Your account will be charged for renewal at the selected plan's rate within 24 hours prior to the end of the current period. Manage your subscription and auto-renewal in Account Settings after purchase. Terms of Use: https://decide.innocoretech.com/terms Privacy Policy:https://decide.innocoretech.com/privacy If you enjoy this app, please leave a review - your feedback is important to us. Contact Us:support@innocoretech.com

Screenshots

Strobe tachometer (RPM meter)4 screens
FunDecider3 screens

Verdict

The call

The clearest difference is in-app purchases: FunDecider at none against Strobe tachometer (RPM meter)'s 2. FunDecider also leads on iOS requirement (12.0 vs 15.6). Strobe tachometer (RPM meter)'s advantage is update cadence (every 4 months vs every 32 months). 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. Strobe tachometer (RPM meter) sells 2 one-off in-app purchases. FunDecider asks for nothing beyond the download.

UpkeepUpdate frequency

Strobe tachometer (RPM meter) ships an update every 4 months, FunDecider every 32 months. The most recent releases landed on October 21, 2026 and October 27, 2026 respectively.

Scorecard3 real differences · 7 level
Strobe tachometer (RPM meter) versus FunDecider: the parameters behind the verdict, then further details
ParameterStrobe tachometer (RPM meter)FunDecider
PriceFreeFree
Rating4.3 (83 ratings) — better—
Positive reviews69.0% of reviews—
Number of ratings83 — better—
Update frequencyEvery 4 months — betterEvery 32 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPodiPhone, iPod
Requires iOS15.612.0 — better
Further details — not scored
Size16 MB30 MB
Age rating4+17+
DeveloperDmitriy KharutskiyInnoCore Limited

In-app purchases

2 purchases

Strobe tachometer (RPM meter)

One-time2
  • Full version of the stroboscopic tachometer$2.99
  • Laser Tachometer and Magnetic$2.99
None

FunDecider

No in-app purchases

Questions

Is Strobe tachometer (RPM meter) free?
Strobe tachometer (RPM meter) is free to download, with in-app purchases available.
Is FunDecider free?
FunDecider is free to download, with no in-app purchases.
Do Strobe tachometer (RPM meter) or FunDecider have ads?
Neither Strobe tachometer (RPM meter) nor FunDecider shows ads.
Which is updated more often, Strobe tachometer (RPM meter) or FunDecider?
Strobe tachometer (RPM meter) ships an update every 4 months, and FunDecider every 32 months. Most recently, Strobe tachometer (RPM meter) was updated on October 21, 2026 and FunDecider on October 27, 2026.

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