KORAKU vs Origami Learn

KORAKU is an interactive educational app that visualizes how light behaves in real time. Bend rays with lenses and mirrors, overlap light as a wave, and explore color and photons to connect the equations with what you see. Developer: Fuji Bit Inc. KORAKU is the optics edition of the "-raku" physics simulation series. It turns the optics of school and university physics into moving pictures, not just formulas. 12 simulations in 3 categories: - Rays & Images - Lens: Trace rays through convex and concave lenses. Change the focal length, object distance and height to see the image switch between real and virtual, inverted and upright. Explore 1/f = 1/a + 1/b. - Mirror: Switch between concave and convex mirrors. Move the radius R and object distance a to see how the image changes around the focal point F and center of curvature C, and why a virtual image appears behind the mirror. - Eye & Glasses (new): See the cornea and lens focus an image on the retina. Choose a normal, nearsighted or farsighted eye and change the viewing distance, glasses power (diopters) and accommodation to see where the image forms and how blurry it looks. One tap sets matching glasses. - Prism: Watch white light split into a spectrum. Change the apex angle, angle of incidence and refractive index to see dispersion bend each color differently, with the deviation and minimum deviation. - Optical fiber: See light travel by total internal reflection. Change the launch angle and refractive indices to explore the critical angle, numerical aperture (NA) and when light leaks into the cladding. - Light as a Wave - Diffraction grating: Change the number of slits, spacing and wavelength to find the bright lines at d sin(theta) = m lambda, and watch them sharpen as slits are added. - Thin film: Recreate the colors of soap bubbles and oil films. Change the thickness, refractive index and angle to shift the bright and dark wavelengths. - Polarization: Rotate a polarizer and an analyzer to see Malus's law, I = I0 cos^2(theta): brightest at 0 and 180 degrees, blocked at 90. - Color & the Nature of Light - Color mixing: Compare additive mixing of light (RGB) with subtractive mixing of paint (CMY) using three sliders. - Rainbow: Follow sunlight as it refracts into a raindrop, reflects inside and refracts out. See why the primary bow appears about 42 degrees from the antisolar point, the secondary about 51 degrees, with the colors reversed. - Blue Sky & Sunset (new): See sunlight scattered in the atmosphere. Switch between Rayleigh scattering (proportional to 1/lambda^4) and Mie scattering (cloud droplets, haze), and change the sun altitude and air density. As the air mass grows, the sky and sun turn from daytime blue to sunset colors. - Photoelectric effect: Shine light on a metal and watch electrons fly out. Change the frequency, intensity and work function to explore E = hf, Kmax = hf - W and the threshold frequency f0, with the visible and UV bands marked. Features: - Clean, modern design (dark and light themes) - Home screen organized by category - Tips and a play button in the control panel - Parameter sliders with results that update in real time - Legends and labels for every symbol and colored ray on screen - An explanation sheet with formulas for every simulation - In landscape, the canvas and control panel are shown side by side - Supports larger text sizes - VoiceOver reads out each screen's result (real or virtual image, total internal reflection, and more) - 73 languages including English and Japanese, following your device language - No sign-in: start exploring right away Price: - Free - In-app purchases: none - Subscriptions: none - Ads: a banner ad by Pangle at the bottom of the screen The "-raku" educational app series: - SUUGAKU - Mathematics - BUTURAKU - Mechanics - DENRAKU - Electromagnetism - HARAKU - Waves - KORAKU - Optics

Origami Learn is a folding simulator, not a picture book. Every one of the 959 steps in this app is real geometry. The paper on screen is a simulated sheet with layers and creases, so you can drag a fold half-way and hold it there, turn the sheet over to see which flap moves, and replay the same crease as many times as you like. Nothing here is a photograph or a video. That is why it can unstick you when a diagram in a book cannot. 148 MODELS, 122 FREE FOREVER 116 origami models, 9 modular pieces built from folded units, and 23 kirigami designs you fold and cut. Cranes, boxes, flowers, animals, insects, stars, snowflakes, and the traditional children's furniture set. Each one is a genuine traditional design, with the region it came from and the paper it wants. A COURSE, NOT A CATALOGUE Nine chapters take you from "what is a valley fold" to bird bases, reverse folds, modular units and open-and-pull. Twelve lessons and seven practice sets, each unlocking the models that use what you just learned. Search the whole path, switch to a chapter grid, or ask for just the next thing in each chapter. LEARN TO READ ORIGAMI BOOKS Beside the live paper, every step is also drawn the way an origami book draws it: the standard symbols, dashed valley and dash-dot mountain creases, and fold arrows anchored to the corner that actually travels. Learn these and the rest of origami literature opens up. BRING IT TO LIFE Finish a model and decorate it. Thirty-six vector stickers — eyes, mouths, whiskers, leaves, stars — in any colour, plus freehand drawing. Print it, share it as a picture, or keep it in your gallery. Twenty models can be set moving and saved as a looping GIF: the flapping bird flaps, the frog jumps, the tulip opens. FOLD WITH YOUR HANDS FULL Say "next", "back" or "again". Speech is recognised entirely on your device and no audio ever leaves it. Or let the app read each step aloud while you keep both hands on the paper. IPHONE, IPAD, MAC AND APPLE WATCH One purchase covers all four. On Apple Watch the Digital Crown becomes a fold scrubber: rotate to close the crease, feel a tap when it lands, and the step moves on by itself. Add a complication and the watch face puts you back at the step you left. Progress follows you between wrist, phone, tablet and desk. MAKE IT YOUR PAPER Choose the colour of both sides of the sheet, per model or everywhere, including a colour-blind-safe pair told apart by lightness rather than hue. Print true-size squares and grids from Paper Tools. Design your own snowflake in Snowflake Studio and watch the cuts mirror around the wedge. BUILT TO BE READ Full VoiceOver in the player, Dynamic Type throughout, Reduce Motion that swaps animation for clear before-and-after states, AA contrast, and Kids Mode that hides anything needing scissors. FIVE LANGUAGES, COMPLETELY English, Tiếng Việt, 日本語, Español and 简体中文 — not only the buttons, but every model name, every step instruction, every tip, lesson and glossary entry. Switch language in Settings and the whole app reloads in it. NO ADS. NO TRACKING. NO ACCOUNT. There is nothing to sign up for and nothing to collect. No analytics, no advertising, no third-party SDKs. Your progress and your photographs stay on your device, and the whole library works offline. Home: https://orlproducts.com/origamilearn.html Privacy Policy: https://orlproducts.com/privacy.html Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Got ideas or feedback? Send them our way: info@orlproducts.com