Comparison

Rail Model Track Calc vs Spark Plug Reader

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

Head to head
About

Rail Model Track Calc

Easily calculate horizontal and vertical dimensions for diagonal railroad model track layouts. Input track length and angle to get precise measurements for combining different track pieces. Avoid guesswork and ensure accurate model railway construction.

Highlights
  • Calculate horizontal and vertical track lengths
  • Input track length and angle
  • Precise measurements in 0.5 mm increments
  • Error margin less than 0.5mm
  • Reset function for calculations
  • Designed for railroad modeling hobbyists
Features
Read full description

Overview This is an application that can calculate the horizontal and vertical lengths when laying out the railroad model tracks diagonally. For example, when a straight track is laid out after laying a curved track(e.g. 45° angle). Or straight tracks after laying out railroad points (e.g. 15°) etc. If you lay out the track diagonally like this, It is necessary to know the horizontal and vertical dimensions in order to combine other tracks to create a layout. But, it is troublesome to calculate the size. There is also need to rely on intuition. So please, use this application. This application you can easily calculate the dimensions of the track. How to use 1. Enter a millimeter number for the track length. 2. Select an angle. 3. The Horizontal, Difference, and Vertical, which are the calculation results, are displayed. Decimal point can be used. Calculation result As the calculation result, the horizontal length (angle 0°), horizontal difference, and vertical length are displayed in units of 0.5 mm. The error of the calculation result is less than 0.5mm Reset button The numbers and angles are reset. Disclaimer This calculator is for the railroad modeling hobby. The calculation results is the numerical value which be calculated by the developer. It may be different from the numerical value by model manufacturer. In particular, commercially available railroad model rails allow for dimensional errors. Therefore, the calculation results do not necessarily represent what the track layout cannot or can be done. This application is subject to change without notice. The developer assumes no responsibility for any loss or claims by third parties which may arise from the use of this application.

About

Spark Plug Reader

Features
Read full description

Plug Read turns a spark plug into a diagnosis, and now it torques the replacement in correctly too. MATCHED BY EYE, NOT BY PART NUMBER Eight appearances, drawn as they come out of an engine. Tap the match and you get what it means and what to check, in the order worth checking it. INSTALL TORQUE, BY THREAD AND SEAT Pick the thread size and seat type, the head material, and get the torque range in both ft-lb and Nm, plus the hand-tight-and-turn fallback for when you do not have a torque wrench. Cross a plug wrong and you either strip the threads or leave it loose enough to blow out under compression, and the difference between right and wrong can be as little as five foot-pounds. THE PLUG IS THE CHEAPEST WINDOW INTO AN ENGINE Five minutes with a plug spanner tells you more about mixture, timing and oil control than an hour of guessing. NO PART NUMBERS, NO DATABASE Nothing here goes out of date, because it works from the plug in your hand and the thread you are installing into rather than a list of engine models. WORKS OFFLINE No account, no signal. The torque table is a published general reference cross-checked across several independent sources, not a measured specification for any specific engine. Manufacturer torque specification always takes precedence.

Screenshots

Rail Model Track Calc4 screens
Spark Plug Reader4 screens

Verdict

The call

The clearest difference is in-app purchases: Rail Model Track Calc at none against Spark Plug Reader's 1. Spark Plug Reader's advantage is ads (none vs shown) and update cadence (every 2 days vs every 18 months). On price, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Spark Plug Reader sells 1 one-off in-app purchase. Rail Model Track Calc asks for nothing beyond the download.

UpkeepUpdate frequency

Rail Model Track Calc ships an update every 18 months, Spark Plug Reader every 2 days. Both last shipped on October 6, 2026.

Scorecard3 real differences · 7 level
Rail Model Track Calc versus Spark Plug Reader: the parameters behind the verdict, then further details
ParameterRail Model Track CalcSpark Plug Reader
PriceFreeFree
Rating1.0 (1 ratings) — better—
Positive reviews0.0% of reviews—
Number of ratings1 — better—
Update frequencyEvery 18 monthsEvery 2 days — better
AdsYesNo — better
In-app purchasesNo — betterYes
MonetizationAd-supported—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.4 — better16.4
Further details — not scored
Size9 MB37 MB
Age rating4+4+
DeveloperNobuyuki KumakuraEVREN YUCEBAS

In-app purchases

None

Rail Model Track Calc

No in-app purchases

1 purchases

Spark Plug Reader

One-time1
  • Full Version$4.99

Questions

Is Rail Model Track Calc free?
Rail Model Track Calc is free to download, with no in-app purchases.
Is Spark Plug Reader free?
Spark Plug Reader is free to download, with in-app purchases available.
Do Rail Model Track Calc or Spark Plug Reader have ads?
Rail Model Track Calc shows ads; Spark Plug Reader does not.
Which is updated more often, Rail Model Track Calc or Spark Plug Reader?
Rail Model Track Calc ships an update every 18 months, and Spark Plug Reader every 2 days. Most recently, Rail Model Track Calc was updated on October 6, 2026 and Spark Plug Reader on October 6, 2026.

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