HARAKU vs Origami Learn

HARAKU is an interactive educational app that visualizes the physics of waves in real time. Designed for students, teachers and anyone curious about science, it lets you control how waves behave just by moving sliders, so you can intuitively connect the equations with what you see. Developer: Fuji Bit Inc. HARAKU is the waves edition of the "-raku" physics simulation series. It helps you understand the wave concepts taught in middle school, high school and university physics as moving pictures, not just formulas. 12 simulations in 3 categories: - Wave basics - Superposition: Combine two sine waves and watch them reinforce or cancel. Change the amplitude, frequency and phase of each wave independently to see the principle of superposition. - Reflection: See the moment a traveling wave reflects at a boundary. Switch between a fixed end (phase inverts) and a free end (phase is kept), with the incident, reflected and total waves shown in three layers. - Standing waves: Watch standing waves on a string fixed at both ends while changing the harmonic. Check the positions of nodes and antinodes and the effect of tension and damping. - Fourier synthesis: See how square, triangle and sawtooth waves are made of sine waves (harmonics). The more terms you add, the closer the sum gets to the target waveform. - Sound waves - Beats: Overlap two waves with slightly different frequencies and feel the beats. The envelope clearly shows how the amplitude changes. - Doppler effect: Drag the source and see the wavefronts bunch up in front and spread out behind. Go past Mach 1 to create a shock wave. - Air column resonance (new): Switch between closed and open pipes and change the length, air temperature and resonance number to see the resonant frequency and wavelength. The motion of air particles (a longitudinal wave) is shown next to a graph that draws the displacement as a transverse wave, so you can find the nodes and antinodes. - Waves in a plane & light - 2D ripples: Tap the screen to place sources; a numerical solution of the wave equation draws the interference pattern in real time. - Interference: See the lines of reinforcement and cancellation made by two point sources. The fringe spacing changes with the source separation, frequency and speed. - Diffraction: See waves spread through a slit according to Huygens' principle. The ratio of slit width to wavelength changes how strongly they diffract. - Refraction: Visualize Snell's law, including how waves bend at a boundary and total internal reflection at large angles. - Thin-film interference (new): See why soap films and oil slicks shine in color by changing the film thickness, refractive index, angle and what lies below (air or glass). The phase shift on reflection, the color seen under white light, a color-vs-thickness strip and a reflectance-vs-wavelength graph are shown together. Features: - Clean, easy-to-read design (dark and light themes) - Home screen organized by category - Intuitive parameter sliders: touch, try and understand - An explanation sheet with formulas for every simulation - On iPad in landscape, the canvas and control panel are shown side by side - 16 languages (Japanese, English, Chinese Simplified/Traditional, Korean, Spanish, Portuguese (Brazil), German, French, Hindi, Indonesian, Russian, Italian, Turkish, Thai, Vietnamese), 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

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