Comparison

PhysicsGraph vs KORAKU

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

Head to head
About

PhysicsGraph

Features
Read full description

You can feel Synthetic wave! 1,Tap color you want to move! 2,Tap screen and move wave! 3,BlueWave + RedWave = GreenWave

About

KORAKU

Features
Read full description

KORAKU is an interactive educational app for exploring optical phenomena through simulation. The fourth in the series following SUUGAKU (Math), BUTURAKU (Physics), and HARAKU (Waves). This time the theme is "Light." From geometrical optics to quantum-scale phenomena, experience ten simulations of how light behaves. [10 Simulations] - Lens (Thin Lens) Observe ray paths and image formation through convex and concave lenses in real time. Adjust focal length, object distance, and object height to experience the thin lens equation (1/f = 1/a + 1/b). - Spherical Mirror Toggle between concave and convex mirrors to visualize image formation. Move the object and change the radius of curvature to see real vs. virtual and upright vs. inverted images. - Prism Dispersion Simulate white light passing through a prism and separating into a rainbow spectrum, based on Snell's law and the Cauchy dispersion formula. - Rainbow Trace light entering a raindrop, refracting, reflecting internally, and exiting. Wavelength-dependent deviation reproduces the primary and secondary rainbows around the antisolar point. - Diffraction Grating Visualize multi-slit interference patterns. Change slit spacing and wavelength to understand the diffraction condition d sin(ฮธ) = mฮป. - Optical Fiber Simulate light propagation by total internal reflection. Adjust the launch angle and refractive indices to learn the relationship between critical angle and numerical aperture (NA). - Polarization Change the angles of the polarizer and analyzer to observe transmitted light intensity following Malus's law (I = Iโ‚€cosยฒฮธ). - Thin Film Interference Reproduce the rainbow colors of soap bubbles and oil films. Adjust film thickness, refractive index, and incident angle to observe interference based on optical path difference. - Color Mixing Compare additive color mixing (RGB light) and subtractive color mixing (CMY pigments). Three channel sliders show the resulting RGB values in real time. - Photoelectric Effect Animate electrons being ejected from a metal by photons. Three sliders for frequency, intensity, and work function let you feel the relationships E = hf, Kโ‚˜โ‚โ‚“ = hf โˆ’ W, and threshold fโ‚€ = W/h. [Features] - Adjust parameters in real time across all simulations - Physics formulas and values displayed in real time - Dark mode / Light mode support - Japanese / English support - iPhone / iPad support [Pricing & In-App Purchases] - The app itself is completely free - No in-app purchases of any kind - No subscriptions - No paid additional content - A small banner ad (Google AdMob) is shown at the bottom of the screen - Ad personalization may use the iOS App Tracking Transparency permission (optional) [Recommended For] - Students studying optics in physics class - Anyone who wants to intuitively understand the properties of light - Teachers looking for teaching materials - Anyone interested in optics

Screenshots

PhysicsGraph2 screens
KORAKU4 screens

Verdict

The call

The clearest difference is ads: PhysicsGraph at none against KORAKU's shown. PhysicsGraph also leads on iOS requirement (9.0 vs 13.0). On price, update cadence, in-app purchases and device support there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

PhysicsGraph ships an update every 5 days, KORAKU weekly. The most recent releases landed on October 7, 2026 and October 2, 2026 respectively.

Scorecard2 real differences ยท 4 level
PhysicsGraph versus KORAKU: the parameters behind the verdict, then further details
ParameterPhysicsGraphKORAKU
PriceFreeFree
Update frequencyEvery 5 days โ€” betterWeekly
AdsNo โ€” betterYes
In-app purchasesNoNo
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS9.0 โ€” better13.0
Further details โ€” not scored
Size12 MB24 MB
Age rating4+4+
DeveloperYaneurabeyaFuji Bit Inc.

In-app purchases

None

PhysicsGraph

No in-app purchases

None

KORAKU

No in-app purchases

Questions

Is PhysicsGraph free?
PhysicsGraph is free to download, with no in-app purchases.
Is KORAKU free?
KORAKU is free to download, with no in-app purchases.
Do PhysicsGraph or KORAKU have ads?
KORAKU shows ads; PhysicsGraph does not.
Which is updated more often, PhysicsGraph or KORAKU?
PhysicsGraph ships an update every 5 days, and KORAKU weekly. Most recently, PhysicsGraph was updated on October 7, 2026 and KORAKU on October 2, 2026.

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