Mullion

Mullion arranges your Mac windows into clean, tiled layouts with a keyboard shortcut or a click — no more dragging and resizing by hand every time you switch tasks. Send a window to the left half, snap two apps side by side, or fill the screen instantly, all without lifting your hands off the keyboard.

HOW IT WORKS Mullion lives in your menu bar. Open its panel or press a shortcut to send the active window to a position — halves, fullscreen, or centered — and it resizes and moves in place. Assign your own keyboard shortcut to every action, so the arrangements you use most are always one keystroke away.

FEATURES

• Snap the active window to the left, right, top, or bottom half
• Fill the screen or center a window instantly
• Trigger every arrangement with a keyboard shortcut
• A menu-bar panel with the full snap grid, always a click away
• Save a layout and restore it in one click

PRO A single one-time unlock adds:

• Quarter and third snap zones, not just halves
• Unlimited saved layouts — restore a whole workspace in one click
• Move windows between displays with a shortcut

PRIVACY Mullion works entirely on your Mac. It uses macOS accessibility permission only to move and resize your windows — nothing ever leaves your device, and there are no accounts, no cloud, and no tracking.