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.
Thin Lens Equation Calc
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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.
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.
- 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
Verdict
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
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.
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.
| Parameter | Thin Lens Equation Calc | Hercules CyclePay |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | — | 4.4 (3.2K ratings) — better |
| Positive reviews | — | 41.1% of reviews |
| Number of ratings | — | 3.2K — better |
| Update frequency | Every 27 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.6 | 12.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 23 MB |
| Age rating | 4+ | 4+ |
| Developer | Nitrio | Hercules 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
Thin Lens Equation Calc
No in-app purchases
Hercules CyclePay
No in-app purchases
Questions
Is Thin Lens Equation Calc free?
Is Hercules CyclePay free?
Do Thin Lens Equation Calc or Hercules CyclePay have ads?
Which is updated more often, Thin Lens Equation Calc or Hercules CyclePay?
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