For iPad and iPhone

Grow trees from a handful of rules.

Write an axiom, add a few rewriting rules, and watch a plant unfold. Built on the classic models from The Algorithmic Beauty of Plants, with a hands-on guide to the history and theory behind them.

Download on TestFlight Get help

A small lab for growing plants

Start from a classic, bend the rules, learn why it works, then put the result on your floor.

Library

Start from the classics

Models from the book by Honda, Aono and Kunii, plus species sketches from Norway spruce to weeping willow. Tune leaves, bark and thickness, then scrub through each generation.

Arbor Lab on iPad showing a silver birch, with the specimen library and leaf and bark controls

Tutorial · 10 chapters

Learn how it works

From Logo’s turtle to Lindenmayer’s rewriting rules, with a playground on every page.

Pro · one-time unlock

Put it in your room

Place your tree in AR, save high-resolution renders and export USDZ models. No subscription.

Arbor Lab on iPhone placing a tree in augmented reality, growing out of a glass bottle in a living room

Editor

Edit the rules directly

Parametric and stochastic productions, defines and tropism. Change an angle or a probability and the tree regrows in 3D.

p1: A −(0.7)→ … 10,128 modules

Arbor Lab on iPad showing an English oak next to the code editor with its L-system rules

Support

Questions, bugs or ideas? Send me an email. I read everything and usually reply within a couple of days.

Which devices are supported?

iPad and iPhone running iPadOS 26 or iOS 26 or later.

How do I restore my Pro purchase?

Open Settings in the app and tap Restore Purchases, signed in with the same Apple Account you bought it with.

What format do 3D exports use?

USDZ, which opens in Quick Look, Reality Composer and most 3D tools. Use the share button to save it to Files or send it to another app.

Reporting a bug

Include your device, iOS version, app version and, if you can, the rules that caused the problem.

Privacy

Effective 4 November 2026

The short version: Arbor Lab doesn’t collect any personal data.

No accounts, no tracking. There’s no sign-up, no analytics and no advertising. Nothing you make leaves your device unless you share or export it yourself.
Your creations stay on your device. Rules, trees and exports are stored locally (and in your iCloud, if you use iCloud backup), not on any server of mine.
Camera use for AR. When you use AR, the camera feed is processed on your device by Apple’s ARKit to place the tree. It isn’t recorded or sent anywhere. Photos you take are saved only where you choose.
Purchases are handled by Apple. Pro and tips go through the App Store. I never see your payment details; Apple’s privacy policy applies to those transactions.
Email. If you write to support, I use your address only to reply, and don’t share it.

If this policy changes, the updated version will be posted on this page with a new date. Questions? Use the email in Support.