Comparison

RayLab vs KAKURAKU

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

Head to head
About

RayLab

Design and simulate optical systems with this powerful tool. Explore 2D and 3D models, perform advanced ray tracing, and analyze optical performance. Ideal for learning or professional design.

Highlights
  • 2D/3D optical modeling
  • Geometric ray tracing
  • Sequential and non-sequential analysis
  • Advanced optical elements
  • Polarization ray tracing
  • Design optimization
  • Glass catalogs
Features
Read full description

RayLab is an application for design and simulation of optics. It can be used either as a learning tool or for the design of real optical systems. Basic version includes: • Ability to model 2D lenses and mirrors • Full control over placement and shape of optical components • Full control over aspheric surface shape parameters • Full geometric ray tracing • Sequential and Non Sequential analysis • Front Focal Length, Back Focal Length, Principle Surface calculations • Sample Models Upgrade to RayLab Pro enables: • 3D Modeling • Advanced Optical Elements such as Lens Arrays, Diffraction Gratings, Prisms, Fresnel Lenses, etc. • Polarization Ray Tracing * Ray Splitting / Beam Splitter modeling • Multi-Configuration Manager and animation functionality • Ability to perform optimizations of design parameters • Ray Transfer Matrix calculation • Various commercial glass catalogs • Zemax Importer • Multiple Analysis Windows: -- Fan Ray Diagram. -- Wavefront Error Plot. -- Grid Distortion Plot. -- Spot Diagram. -- Chromatic Aberration. -- Gaussian Spot Size. -- Polarization Analyzer. Upgrade is available with in-app purchases of various modules OR as a full featured subscription. • The subscription offers a 7 day free trial period. Subscription begins immediately but payment will only be charged to iTunes Account at the end of the trial period. • Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. • The account will be charged for renewal within 24-hours prior to the end of the current period, at the same monthly price as the original subscription. • You may manage your subscriptions and auto-renewal may be turned off by going to your iTunes Account Settings after purchase. • No cancellation of the current subscription is allowed during active subscription period. • Any unused portion of a free trial period will be forfeited if the subscription is cancelled. Privacy Policy and Terms of Use: https://www.raymak.com/wp/privacy-policy

About

KAKURAKU

Features
Read full description

KAKURAKU is an interactive educational app for experiencing probability paradoxes through hands-on simulation. The 10th installment in the SUUGAKU / BUTURAKU / DENRAKU / HARAKU / NETURAKU / KORAKU / RYURAKU series. The theme is "probability." Experience 12 famous probability paradoxes through four interactive phases. [4 Phases for Deep Understanding] 1. Intuition Quiz Answer with your gut feeling first. Most people get it wrong. 2. Simulation Run hundreds of trials and see the results with your own eyes. 3. Explanation Why does intuition fail? Mathematical explanations bring that "aha" moment. 4. Comprehension Check Test your true understanding with applied questions. [12 Probability Paradoxes] 1. The Door Trap — Monty Hall Problem (switching wins 2/3 of the time?) 2. Miracle Classroom — Birthday Paradox (50%+ chance with just 23 people?) 3. The Gold Box — Bertrand's Box (your 1/2 intuition is wrong?) 4. Reversal Statistics — Simpson's Paradox (parts and whole tell opposite stories?) 5. Envelope Dilemma — Two Envelope Problem (should you always switch?) 6. Test Trap — False Positive Problem (positive result yet only 16% infected?) 7. Sleeping Princess — Sleeping Beauty Problem (1/2 or 1/3? Still unsolved) 8. Endless Bus — Bus Waiting Paradox (average 5 min but you wait 10?) 9. Red Streak — Gambler's Fallacy (black is "due" next?) 10. Infinite Gamble — St. Petersburg Paradox (infinite expected value?) 11. Warden's Verdict — Three Prisoners Problem (does A's fate change?) 12. The Predictor's Boxes — Newcomb's Paradox (one-box or two-box?) [Features] - Interactive simulations — see it to believe it - Run single trials, 100x batches, or 1000x batches to watch probabilities converge - Live formulas and numerical values - Dark mode / Light mode - Japanese / English support - Works offline (network is used only for ad delivery) [Monetization & Ads] - This app is free to download and use - No in-app purchases, no subscriptions, no paid unlocks - A banner ad (Google AdMob) is shown at the bottom of the screen - An interstitial ad may be shown when you clear a stage - On iOS, personalized ads are only delivered after the user grants App Tracking Transparency (ATT) permission [Recommended For] - Students studying probability and statistics - Anyone curious about the gap between intuition and mathematics - Teachers looking for interactive teaching materials - Anyone who wants to truly internalize "why is it that way?"

Screenshots

RayLab4 screens
KAKURAKU4 screens

Verdict

The call

The clearest difference is in-app purchases: KAKURAKU at none against RayLab's 10. KAKURAKU also leads on update cadence (every 2 weeks vs every 6 weeks). RayLab's advantage is iOS requirement (11.0 vs 13.0). 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. RayLab sells 10 in-app purchases, starting at $3.99 per month. KAKURAKU asks for nothing beyond the download.

UpkeepUpdate frequency

RayLab ships an update every 6 weeks, KAKURAKU every 2 weeks. The most recent releases landed on July 29, 2026 and September 10, 2026 respectively.

Scorecard3 real differences · 7 level
RayLab versus KAKURAKU: the parameters behind the verdict, then further details
ParameterRayLabKAKURAKU
PriceFreeFree
Rating4.6 (63 ratings) — better—
Positive reviews75.0% of reviews—
Number of ratings63 — better—
Update frequencyEvery 6 weeksEvery 2 weeks — better
AdsYesYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS11.0 — better13.0
Further details — not scored
Size39 MB24 MB
Age rating4+4+
DeveloperKamyar GhandiFuji Bit Inc.

In-app purchases

10 purchases

RayLab

Subscriptions1
  • RayLab Pro Subscription7 Days trial$3.991 Month
One-time9
  • RayLab Pro UpgradeFree
  • Schott Glass Catalog$0.99
  • Custom Glass Editor$0.99
Show 6 more
  • Advanced Optical Elements$1.99
  • Source and Lens Arrays$1.99
  • Solver/Optimizer Module$3.99
  • 3D Modeling$4.99
  • RayLab Pro 2$19.99
  • RayLab Pro Bundle$19.99
None

KAKURAKU

No in-app purchases

Questions

Is RayLab free?
RayLab is free to download, with in-app purchases available.
Is KAKURAKU free?
KAKURAKU is free to download, with no in-app purchases.
Do RayLab or KAKURAKU have ads?
Both RayLab and KAKURAKU show ads.
Which is updated more often, RayLab or KAKURAKU?
RayLab ships an update every 6 weeks, and KAKURAKU every 2 weeks. Most recently, RayLab was updated on July 29, 2026 and KAKURAKU on September 10, 2026.

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