Chladni: Sound Patterns
Sand patterns drawn by sound
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Send sound through a plate and the sand gathers where the plate is still, drawing a pattern. Four plates, twenty patterns. Free with ads; one purchase removes them.
In the 18th century the physicist Ernst Chladni drew a bow across a metal plate scattered with sand, and the sand arranged itself into a pattern. When a plate vibrates, certain lines stay perfectly still. The sand settles along those quiet lines, and the pattern appears. These are Chladni figures.
This app recreates that phenomenon in the palm of your hand. Three thousand grains tremble on the screen and slowly gather along the nodal lines. It is made for watching that settling happen.
What you can do
- Four plates, twenty patterns: switch between square, circle, triangle and ring plates. Each has five patterns, twenty in all. Every plate has its own sand colours and its own range of tones.
- Turn the dial: rotating the dial changes the pattern. The sand is not reset. It slowly rearranges itself from the shape it is in into the new one, and that rearrangement is the part worth watching.
- Hear the tone: each pattern has its own pitch, and the range of tones moves with the plate you choose. Turn the sound off whenever you want to watch in silence.
- Sing to the sand: turn on the microphone and hum a clear, steady note. The pitch of your voice selects a pattern within the current plate, and the volume sets how wildly the sand dances. Your voice is analysed on the device as it happens. Nothing is recorded and nothing is sent anywhere.
- Fill the collection: save the patterns you like with a name of your own. The collection has twenty slots, and each saved pattern is given one to three stars according to how intricate it is. Mark favourites and filter to show only those. Tap a saved pattern to bring it back to the screen.
- Export a wallpaper: save the current pattern as a 1179 x 2556 PNG in your Photos. It is not a snapshot of the screen. Grains of sand are redrawn along the nodal lines computed from the equations, so the sandy texture holds up at full resolution.
The mathematics is computed, not drawn
The circular plate uses Bessel functions and the triangle uses the exact Lame solution, and so on for each shape. Nothing is a prepared picture being played back. Every pattern comes from an equation solved on the spot.
Free, and what the one-time purchase adds
Watching, switching plates, sound, microphone mode, the collection and favourites are all free. Exporting a wallpaper is free too, but while the app is free the exported image carries a faint watermark of the app name, and a small banner ad sits at the bottom of the screen (it is hidden while the collection is open and while the opening screen is showing).
A single one-time purchase removes that watermark and removes the ads as well. It is the only thing for sale and it is not a subscription. Without it you can still watch every pattern, fill the whole collection, and save wallpapers.
Good to know
- Ads: to keep the app free, a small banner ad supplied by Google is shown at the bottom of the screen. The one-time purchase removes it.
- To show those ads, information about your device and about the ads you see may be collected by Google. If you decline the tracking request shown at launch, the advertising identifier is not used. Every feature of the app works either way.
- No account required
- The app connects only to load ads and to buy or restore the one-time purchase
- Your collection is stored only on this device
- Your voice is analysed on your device, never recorded and never transmitted
- Available in 33 languages
Take a moment and watch the pattern rise quietly out of the sand.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
What's new in 1.1
- Available in 33 languages. The app follows the language of your device.
- A small banner ad now sits at the bottom of the screen. Everything the app does stays free. A single one-time purchase removes both the ads and the wallpaper watermark. If you have already bought it, the ads are gone for you too, at no extra cost.
- The first time you open the app, it shows the tracking request used for the ads. If you decline, the advertising identifier is not used and every feature still works.
- Once you have found ten patterns, the app asks one time whether you would like to leave a rating.
Thank you for watching the sand settle quietly along the nodal lines.
The developer, Takashi Nemoto, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Location
- Identifiers
- Usage Data
- Diagnostics
Data Linked to You
The following data may be collected and linked to your identity:
- Location
- Identifiers
- Usage Data
- Diagnostics
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Takashi Nemoto
- Size
- 4.7 MB
- Category
- Entertainment
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 32 more
- English, Arabic, Catalan, Croatian, Czech, Danish, Dutch, Finnish, French, German, Greek, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian Bokmål, Polish, Portuguese, Romanian, Russian, Simplified Chinese, Slovak, Spanish, Swedish, Thai, Traditional Chinese, Turkish, Ukrainian, Vietnamese
- Age Rating
4+
- 4+
- Contains
Advertising
- In-App Purchases
Yes
- Remove Ads and Watermark $0.99
- Copyright
- © 2026 Takashi Nemoto