Comparison

Thin Lens Equation Calc vs Hercules CyclePay

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

Head to head
About

Thin Lens Equation Calc

Features
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Thin Lens Calc. is the essential optics calculator for students, teachers, and engineers. Instantly solve the thin lens equation (1/f = 1/do + 1/di) for any unknown variable — focal length, object distance, or image distance — with real-time results and an interactive ray diagram. SOLVE ANY VARIABLE Select what you want to find, enter the two known values, and get the answer instantly. The app auto-calculates as you type or drag the slider, so you can explore how changing one parameter affects the others. INTERACTIVE RAY DIAGRAM Watch the ray diagram update live as you adjust values. See how light passes through converging and diverging lenses, where real and inverted images form, and how virtual images appear on the same side as the object. A visual way to build intuition for optics. STEP-BY-STEP SOLUTIONS Tap to reveal a full algebraic walkthrough of each calculation — from the starting equation through substitution, simplification, and unit conversion. Perfect for checking homework or learning the method. UNIT CONVERSION BUILT IN Switch freely between millimeters, centimeters, and meters for each field independently. The app handles all conversions internally so you never have to convert by hand. FEATURES • Solve for focal length (f), object distance (do), or image distance (di) • Live-updating ray diagram with object and image arrows • Step-by-step solution breakdown • Unit pickers (mm, cm, m, in, ft) per field • Adjustable decimal precision (0–10 digits) • Tap-to-copy results to clipboard • Save calculations to history (SwiftData) • Negative value support for virtual images and diverging lenses • Scientific notation for extreme values • No ads, no subscriptions, no internet required Built for physics students studying geometric optics, teachers preparing demonstrations, and anyone who needs a fast, reliable thin lens calculator on their iPhone or iPad. Thanks for your support, and please visit nitrio.com for more apps for your iOS devices.

About

Hercules CyclePay

Easily start washing machine and dryer cycles using your phone at participating laundry locations. Send service requests directly through the app for any issues encountered.

Highlights
  • Start washer and dryer cycles
  • Phone-based cycle activation
  • Send service requests
  • Real-time machine status (select locations)
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IMPORTANT: ONLY WORKS IN HERCULES LAUNDRY LOCATIONS. LOOK FOR SIGNAGE. You can easily start cycles on washers and dryers in your laundry room with your phone. You can also send service requests if needed. * Real-time machine status only at select locations.

Screenshots

Thin Lens Equation Calc4 screens
Hercules CyclePay4 screens

Verdict

The call

The clearest difference is price: Hercules CyclePay at Free against Thin Lens Equation Calc's $2.99. Hercules CyclePay also leads on update cadence (every 2 months vs every 27 months) and iOS requirement (12.0 vs 17.6). On ads, in-app purchases 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

Hercules CyclePay is free to download; Thin Lens Equation Calc costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Thin Lens Equation Calc ships an update every 27 months, Hercules CyclePay every 2 months. The most recent releases landed on October 25, 2026 and November 3, 2026 respectively.

Scorecard3 real differences · 7 level
Thin Lens Equation Calc versus Hercules CyclePay: the parameters behind the verdict, then further details
ParameterThin Lens Equation CalcHercules CyclePay
Price$2.99Free — better
Rating—4.4 (3.2K ratings) — better
Positive reviews—41.1% of reviews
Number of ratings—3.2K — better
Update frequencyEvery 27 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNoNo
Monetization—Free
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.612.0 — better
Further details — not scored
Size1 MB23 MB
Age rating4+4+
DeveloperNitrioHercules Corp

Bugs and requests

Thin Lens Equation Calc

Not enough reviews yet to summarise bugs or requests.

Hercules CyclePay

Reported bugs

4 issues
  • Machines not connecting to app
  • Incorrect cycle time reporting
  • Charges without starting machines
  • Frequent app crashes

Requested features

4 requests
  • Allow manual time input for dryers
  • Improve machine status visibility
  • Implement remote machine control
  • Save payment information

In-app purchases

None

Thin Lens Equation Calc

No in-app purchases

None

Hercules CyclePay

No in-app purchases

Questions

Is Thin Lens Equation Calc free?
Thin Lens Equation Calc costs $2.99, with no in-app purchases.
Is Hercules CyclePay free?
Hercules CyclePay is free to download, with no in-app purchases.
Do Thin Lens Equation Calc or Hercules CyclePay have ads?
Neither Thin Lens Equation Calc nor Hercules CyclePay shows ads.
Which is updated more often, Thin Lens Equation Calc or Hercules CyclePay?
Thin Lens Equation Calc ships an update every 27 months, and Hercules CyclePay every 2 months. Most recently, Thin Lens Equation Calc was updated on October 25, 2026 and Hercules CyclePay on November 3, 2026.

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