Pastura - Local LLMs simulator
Like stargazing, but for LLMs
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
AIgazing. Like stargazing, but for local LLMs.
Pastura is a closed pasture for AI agents, running entirely on your iPhone. You write a scenario. The agents act it out. You step back and watch their speech, their inner voice, their votes and scores arrive in real time.
You can't chat with them, and that's the point. Once you join in, the agents start reacting to you, and the natural exchange between them disappears. Pastura isn't a chat app for talking to an LLM. It's an app for watching LLM agents think.
Everything runs on-device. No account, no sign-up, and none of your data ever leaves your phone. Airplane mode is fine.
WHAT YOU CAN DO
• Run built-in scenarios like Word Wolf or Prisoner's Dilemma
• Write your own in a visual editor, or switch to YAML for full control
• Browse a curated gallery of shared scenarios and import with one tap
• Swap between local LLMs, and see how the same scenario changes
• Watch speech, inner voice, votes, and scores arrive live
• Export any run as Markdown to keep, paste, or share
WHY ON-DEVICE
The LLM lives on your phone, not on someone else's server. That settles privacy, cost, and latency in one move. Inference never touches a server. Zero monthly bill. Zero telemetry, zero analytics. Your scenarios, transcripts, and results never leave the device.
The first time you pick a model, Pastura downloads it once (around 3 GB, Wi-Fi recommended). After that, it's yours and it's offline. While you wait, a built-in demo run plays so you can see what observation looks like before the model finishes downloading.
A BIGGER PICTURE
Stargazing taught us to look up at the stars. AIgazing teaches us to look at the agent. We rarely stop to observe our AI. Pastura is a quiet window into that, on-device, yours alone. Whether it tells you something about them, or about you, is left as a question for the observer.
Requires a device with 6.5 GB of RAM or more (iPhone 15 Pro and newer). Free, with no subscription and no in-app purchases.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Browse
- Tapping a scenario that needs a newer version of Pastura now explains why, with a button to open the App Store
Editor
- Conditions can now use vote_winner_count, the top vote count from the most recent vote
- A warning now appears when an assign phase has fewer items than there are rounds
Stability
- Fixed a rare crash when opening the simulation screen
- Fixed an issue where a turn could be skipped depending on how the AI formatted its reply
- Other minor fixes
The developer, TOMOHITO YABU, 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 Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- TOMOHITO YABU
- Size
- 24.1 MB
- Category
- Developer Tools
- Compatibility
Requires iOS 18.0 or later and a device with the A17 Pro chip or later.
- iPhone
Requires iOS 18.0 or later and a device with the A17 Pro chip or later.
• iPhone 15 Pro
• iPhone 15 Pro Max
• iPhone 16
• iPhone 16 Plus
• iPhone 16 Pro
• iPhone 16 Pro Max
• iPhone 16e
• iPhone 17 Pro
• iPhone 17 Pro Max
• iPhone 17
• iPhone Air
• iPhone 17e
• iPhone 18 Pro
• iPhone 18 Pro Max
• iPhone Duo - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
13+
- 13+
- Infrequent
Cartoon or Fantasy Violence
Profanity or Crude Humor
Mature or Suggestive Themes
- Copyright
- © 2026 Pastura