Light Lab vs KORAKU

Move light. Refract it. Reflect it. Light Lab is an interactive science app where you learn by playing with light. 【Discover the Magic of Light】 Touch the screen and move the light source. Rotate lenses and change refractive indices. Watch light rays change in real-time! Create rainbows, bounce light off mirrors. "Why does this happen?" As you play, you'll naturally understand how light works. 【Perfect For】 ・Students learning about light in elementary or middle school ・Anyone studying light propagation, reflection, and refraction ・Teachers who want to make science class more engaging ・Anyone curious about optics 【What You Can Do】 ◆ Real-Time Light Manipulation Move light sources and lenses to see light rays change instantly. Rotation, translation, refractive index changes—all operations reflect in real-time. ◆ Place Various Lenses Triangular prisms, convex lenses, concave lenses, diamonds, spheres, mirrors, and more. Place up to 10 lenses simultaneously to recreate complex light behaviors. ※2 lens types are free (triangle prism, biconvex lens) ◆ 3 Types of Light Sources ・Parallel: Like sunlight ・Spotlight: Like a light bulb ・Dispersion: Rainbow-colored light ◆ Create Animations Save lens and light arrangements as "scenes." Connect multiple scenes to create animations showing how light transforms. ◆ Save and Share Save your creations in the app. Generate QR codes to share with friends and classmates. 【For Teachers】 Designed as an educational tool for classroom use. ・Visually understand light propagation, reflection, and refraction ・Simulate phenomena that are difficult to explain, like total internal reflection and dispersion ・Students can experiment independently—perfect for inquiry-based learning ・Save and share scenes as teaching materials Try it for free first! 【Features in Detail】 ＜Light Source Adjustments＞ ・Position and rotation ・Adjust number of rays and width ＜Lens Adjustments＞ ・Position and rotation ・Refractive index settings ・Size adjustment ・Curvature adjustment for convex and concave lenses ＜Scene Features＞ ・Create up to 5 scenes ・Smooth animations between scenes ＜File Features＞ ・Local saving ・QR code sharing 【Pricing】 Basic features are free. ◆ Lens Unlock ($5.99/ One-time purchase) Unlock premium lenses (plano-convex lens, biconcave lens, diamond, sphere, mirror, reflector). ◆ Lens Ticket Issuing Feature ($11.99/ One-time purchase) ※Requires "Lens Unlock" purchase first Generate QR codes to unlock all lenses on other devices for 1 year. Tickets can be issued repeatedly—perfect for teachers adopting the app school-wide or classroom-wide. 【Privacy】 ・No personal information is collected ・Works offline by default ・Internet connection required only for accurate time retrieval when using Lens Ticket feature 【Requirements】 ・iPhone / iPad ・iOS 16.0 or later 【Support】 Detailed instructions are available in the in-app "How to Use" menu. For questions, contact us via the support page. Bring the world of light closer. Let's play with light!

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(θ) = mλ. - 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 = I₀cos²θ). - 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, Kₘₐₓ = hf − W, and threshold f₀ = 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