Shortcuts and quick layouts
Send a window left, right, to the center or to full size with a keyboard shortcut or a quick layout.
Save your setup.Get back to work.
Mullion saves your Mac window layouts and puts every window back with one click, with Undo if you change your mind.
$2.99 launch price, then $4.99
One-time purchase · Free updates · Apple Silicon, macOS 26+
Mullion
Your setups
Writing4 windows · Main display
Code review3 windows · 2 displays
Morning inbox2 windows · Main display
Choose a setupWriting restoredUndoUndo
Set it up once. Come back in one click.
Mullion remembers each window by its app and title, along with its place and size.
- 01
Arrange
Open the apps you use for a task and put each window where you want it.
- 02
Save
Choose Save a setup, give it a name like Writing, and pick the windows to include.
- 03
Restore and Undo
Click the setup and every window moves back into place. Undo returns them to where they were.
Keep the documents you need open so a setup can find them. Mullion restores window positions and opens apps; it does not reopen specific documents or browser tabs.
Small tools for the way you already work.
Your own window sizes
Save the sizes you use most and apply them to any window.
A folder and a link per setup
Keep a project folder and a web link with a setup and open them with its windows.
Opens your apps
Open installed apps from Mullion, then put their windows where they belong.
A small control in a corner
Keep a compact Mullion control in a screen corner and open the full panel when you need it.
Plain-language commands, on your Mac
Type what you want, like “Make this window bigger and center it.” Common commands work without a model. Others run locally with Apple Intelligence or an existing Atris local runtime.
Your agent can arrange windows too.
Mullion includes a local tool pack for compatible agents: a JSON-lines protocol and an MCP adapter.
- InspectSee open windows and displays.
- PreviewShow the new layout before anything moves.
- ApplyMove only the windows it chose.
- UndoPut them back.
{"id":"1","op":"inspect"}
{"id":"2","op":"preview","windowId":"…","zone":"leftHalf"}
{"id":"3","op":"apply","token":"…"}
{"id":"4","op":"undo"}Everything runs on your Mac, with no remote control port. Window titles and positions go to the agent you connect, which may send them to its model provider.
Set up an agentPay once. No subscription.
Mullion for Mac
$2.99launch price, then $4.99
Requires an Apple Silicon Mac with macOS 26 or later and Accessibility permission. Payment is handled by Stripe. The seller is Atris Labs, and the charge on your card statement will mention Mullion.
- Free updates, now and later
- No subscription and no account
- Signed and notarized by Apple, so it opens normally
- Download link right after payment, and by email
- 14-day refundIf Mullion is not right for you, email support@atris.ai within 14 days for a full refund.
Questions
What do I need to run Mullion?
An Apple Silicon Mac with macOS 26 or later. Mullion asks for Accessibility permission so it can move and resize windows.
Can I get a refund?
Yes. If Mullion is not right for you, email support@atris.ai within 14 days for a full refund.
What updates are included?
All of them. Every Mullion update is free, and your download link always gets the newest version.
What stays on my Mac?
Your setups are stored on your Mac, and language commands run locally. If you connect an agent, it receives window titles and positions and may send them to its model provider.
Do I need an AI model?
No. Setups, shortcuts and quick layouts work without one, and so do common commands like “center this window.” Other language commands use Apple Intelligence or an existing Atris local runtime.
Can Mullion reopen my files and browser tabs?
No. Mullion restores window positions and opens apps. It does not reopen specific documents or tabs, so keep the documents you need open and your setup can find them.
How do I get Mullion after I pay?
Your download link appears right after payment, and we email it to you too. Mullion is signed and notarized by Apple, so it opens normally.
Put your windows back in one click.
One-time purchase · 14-day refund · Apple Silicon, macOS 26+