AltTab

That's a great question, as AltTab is one of the most popular third-party applications for macOS power users, especially those who switch between Mac and Windows environments.

AltTab is a free and open-source utility for macOS that brings the powerful, window-centric behavior of the Windows \text{Alt} + \text{Tab}$ shortcut to the Mac.

Why AltTab is popular on Mac

The default window management on macOS uses two different shortcuts:

AltTab unifies this process by allowing you to switch between all open windows across all applications with a single, continuous action.

Key Features

• Window Previews (Thumbnails): When you press the customizable shortcut (by default, $\text{Option} + \text{Tab}$), it displays a large, interactive overlay with live visual thumbnails of every single open window.⁷

• Unified Window Switching: It treats all windows—regardless of the app—as a single, chronological list, letting you instantly jump to any window you were recently using.

• Window Management Actions: From the switcher interface, you can perform quick actions on a selected window or app:

  • Close the window ($\text{W}$).

  • Minimize the window ($\text{M}$).

  • Quit the entire application ($\text{Q}$).

• Customization: The app offers extensive preferences to change the trigger shortcut, adjust the appearance (e.g., Windows 10 vs. macOS theme), change thumbnail size, and blacklist apps you don't want to see in the switcher.

• Compatibility: It is compatible with macOS versions 10.12 (Sierra) up to the latest release and runs natively on both Apple Silicon (M-series) and Intel Macs.

In short, AltTab is considered a must-have tool for anyone who juggles many open windows and wants a faster, more visual, and keyboard-driven way to switch between them on their Mac.