Contain

Contain is a window container application designed specifically for macOS.

It collects your open documents, browsers, terminals, and other physical windows into a single, tabbed window. Clicking a tab allows for quick switching, and clicking ↗ or pressing ⌘W precisely returns the window to its original position on the desktop—it’s not a copy or mirror, but the original window itself. It supports grouping by window rather than application; three documents from the same editor will become three separate tabs. No keyboard shortcuts need to be configured or learned; simply open the desired window and select it from the grid to include it in the container. When finished, release it with a single click to return everything to its original location. The application helps reduce the hassle of repeatedly using ⌘-Tab to find windows, concentrating editors, terminals, and browsers into a single, freely dockable window, ideal for organizing temporary workspaces and easily restoring them. Compatible with macOS 13 or later, requiring only one system permission, Apple-signed and certified, all operations are performed locally without any data analysis or collection, instantly making a cluttered desktop neat and organized while retaining the flexibility to split the workspace at any time.