A vs HARAKU
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
A
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This app uses numerous animations and test questions to explain high school level physics. It aims to give a sensory understanding of physics. It contains a lot of content, such as a list of formulas and explanations of the basics of mathematics. It consists of the following contents. 1. Topics --- The basic principles of physics are explained through animation. 2. Practical Explanation --- The behavior of cubes, springs, rigid bodies, etc. is displayed through animation. Detailed explanations, graphs, various values such as velocity and displacement, and formulas are displayed. 3. Test --- Simple test questions are given. If you have difficulty doing the math in your head, you can use notes to calculate. 4. Formula display --- Formulas can be displayed in a list. Simple explanations are also provided. Please try. This app will show ads, but if you buy it for about $ 5, the ads will not show. The price fluctuates in accordance with the exchange rate. *Currently, only mechanics is supported, but we plan to add more fields in the future. We also plan to add and change animations and tests. If you have any comments or find any errors, please let us know in the rating section. ///////////////////////////////////////////////// Current main contents ・Mechanics --- Equation of motion, momentum, impulse, mechanical energy, work, dynamic friction, static friction, law of inertia, simple harmonic motion, simple pendulum, moment of force, center of gravity
HARAKU
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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
Screenshots
Verdict
The clearest difference is in-app purchases: HARAKU at none against A's 1. HARAKU also leads on iOS requirement (15.0 vs 18.0). A's advantage is ads (none vs shown). On price, update cadence 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
Both are free to download. A sells 1 one-off in-app purchase. HARAKU asks for nothing beyond the download.
A ships an update every 2 weeks, HARAKU every 10 days. The most recent releases landed on October 27, 2026 and November 4, 2026 respectively.
| Parameter | A | HARAKU |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 2 weeks | Every 10 days — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | No — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 18.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 271 MB | 24 MB |
| Age rating | 4+ | 4+ |
| Developer | Ogumo Co., Ltd. | Fuji Bit Inc. |
In-app purchases
A
- Hide ads$5.99
HARAKU
No in-app purchases









