# Grainfall: Falling Sand — Physics sandbox particle toy

> Physics sandbox particle toy (iPhone/iPad app by John Haas.)

- Source: https://appshunter.io/ios/app/grainfall-falling-sand/id6797610785 (this page in markdown: same URL + `.md`)
- Developer: [John Haas](https://appshunter.io/developer/356064826)
- Category: Games, Entertainment, Simulation
- Price: Free with in-app purchases
- Age rating: 12+
- Requires: iOS 14.0 · 23 MB
- Languages: American English
- Released: 2026-08-21
- Data updated: 2026-09-07
- User reviews in markdown: https://appshunter.io/ios/app/grainfall-falling-sand/id6797610785/reviews.md

## What is Grainfall?

Grainfall is a falling sand toy. Pick a material, drag across the screen, and watch it react with whatever is already there.

Sand piles up and slides back down. Dig a hole and water will find it. Oil floats on top of water, and oil burns. Plants drink from standing water and creep toward it. Fire spreads, leaves ash behind, and boils water into steam that drifts up, cools off, and comes back down as rain.

There is no score and nothing to unlock by playing. What you get is twelve materials that all react to each other, and the fun is working out how. Build a glass tank and fill it with acid, since glass is the one thing acid cannot chew through. Pour lava into water and it sets into stone. Light one end of a gunpowder trail and follow it along.

Hit record at any point and Grainfall turns what happened into a video, with sound built from the same events you just watched. Save a world and it keeps a picture of itself in your list. Send one to a friend as a small file and it opens straight into their copy.

FREE
• Sand, water, oil, plant, fire and wall
• The full simulation, running at 60fps
• Record and export video, with a small watermark in the corner
• Your world saves itself and is waiting when you come back

PRO - One time purchase
• Six more materials: acid, glass, lava, ice, gunpowder, fireworks
• Video export with the watermark gone
• Save as many worlds as you want, name them, load them back
• Send worlds to friends as .grain files
• Four color themes
• Tilt gravity, so leaning your phone pours everything sideways

A FEW THINGS WORTH TRYING
• Float oil on water and drop in a single flame
• Fill a glass tank with acid
• Pour lava into the sea and watch the steam come off it
• Light a gunpowder trail at one end
• Set off enough fireworks that the falling sparks catch your plants

Every material makes its own sound. No account, no ads, nothing collected, and it all works offline.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Grainfall Pro | $0.99 | one-time |



## Version history (last 1 release)

### 1.0.0 — 2026-08-21

No release notes.

## More apps by John Haas

- [iSplatter: Splatter Paint Art](https://appshunter.io/ios/app/isplatter-splatter-paint-art/id356064821)
- [MahWins: Mahjong Game Tracker](https://appshunter.io/ios/app/mahwins-mahjong-game-tracker/id6761798566)
- [Text Editor](https://appshunter.io/ios/app/text-editor/id6777578899)
- [NetKit: Ping & Network Tools](https://appshunter.io/ios/app/netkit-ping-and-network-tools/id6780238278)
- [Cron Lab: Crontab Editor](https://appshunter.io/ios/app/cron-lab-crontab-editor/id6783486115)

All apps by John Haas: https://appshunter.io/developer/356064826

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-07.*