AppWindow

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A macOS window switcher focused on a single purpose: switching between apps and windows in a more natural way. Inspired by Contexts, it keeps the core idea and enhances the parts that matter most.

When using the native Cmd+Tab to switch applications, you cannot see the windows and can only cycle through apps one by one. The native `Cmd+`` within the current app is also a slow trial-and-error process. AppWindow turns both into something visible, previewable, and mouse-friendly.

Features

Cmd+Tab — Application switcher

Hold Cmd and press Tab; a horizontal icon panel appears in the center of the screen with a size close to the native one:

• Tab / → moves forward, Shift+Tab / ← / ` moves backward
• ↑ / ↓ selects a window from the highlighted app's window list; releasing Cmd switches directly to that window
• Mouse: hover over icons or window rows to move the highlight, click to switch immediately, use the scroll wheel to switch apps, and scroll on the window list to browse
• Applications are ordered by recent use; when the window count exceeds the visible rows, the list scrolls continuously with up/down indicators
• One panel is shown per screen, and state remains synchronized across screens

Cmd+` — Current app window switcher

Hold Cmd and press `; a popup appears in the center of the screen showing all windows of the current app at about 70% of the screen height:

• Each press of ` immediately switches to the next window: keep pressing to cycle through all windows in order; the window you just left is moved to the end of the cycle and returns only after the rest are visited; release and press again to continue moving forward
• ↑ / ↓ moves one row and switches immediately
• Mouse: hover to move the highlight without switching, click to select a window and dismiss the panel, use the scroll wheel to scroll the list
• Single-window apps still show the popup (to quickly return to that window)

Other

• Esc or clicking outside the panel dismisses it (Cmd+`` switch actions are not undone, matching native behavior; Cmd+Tab` is canceled before release)
• The panel is a non-active window, so it does not steal keyboard focus and stays aligned with your actions
• Requires the system appearance in light/dark mode, with a translucent frosted-glass background
• Menu bar app (no Dock icon); the Settings window (⌘,) hosts configurable trigger keys, the full panel geometry (icon size, row height, panel width, spacing, corner radii, fonts — with live previews), glass mode & blur strength, launch at login, the update channel and diagnostics. While open, the Settings window itself appears in the Cmd+Tab list

Installation

Download

Download the latest DMG from Releases, open it, and drag AppWindow into Applications.

On first launch, enable AppWindow in System Settings → Privacy & Security → Accessibility (the menu bar icon can open this directly).

If the first launch shows: “Cannot verify that AppWindow.app is malicious” (on macOS 15/26, the right-click “Open” option is no longer available), allow it once using either method below:

1. GUI: click “Done” in the prompt, then open System Settings → Privacy & Security and click “Open Anyway” in the “Security” section near the bottom
2. Terminal: xattr -dr com.apple.quarantine /Applications/AppWindow.app

Updates

AppWindow updates itself in place via Sparkle: use Check for Updates… in the menu bar, or leave the default automatic update check on (once a day). New versions are downloaded, verified and installed inside the app.

Pre-release builds go to a beta channel; opt in via Settings → 更新 → 参与测试版. Stable releases are always visible regardless of the channel setting.

Versions installed before auto-update was introduced need one manual install of the latest DMG; after that, updates happen in-app. The Gatekeeper prompt above only affects that first manual install.

Build from source

Requirements: macOS 14+, Xcode Command Line Tools.

./scripts/build-app.sh      # Build and assemble AppWindow.app
./scripts/package-dmg.sh    # Optional: package a DMG

The first build fetches the Sparkle dependency via SPM (requires access to GitHub).

Known limitations

• Switching across Spaces / full-screen apps depends on system activate behavior; in some cases it may not jump to the target window's Space
• Uses the private API _AXUIElementGetWindow to match CGWindow and AXWindow objects (resolved dynamically via dlsym; if unavailable, it falls back to window bounds matching); therefore it cannot be submitted to the App Store
• Trigger keys are matched by physical keycode and are configurable in Settings; they do not follow system-level custom shortcut mappings
• Window titles come from the Accessibility API and do not require screen recording permission

Technical implementation

Swift + AppKit (built with SPM). Core components:

Sources/Context/
├── main.swift              # Entry point; accessory app (no Dock icon)
├── AppDelegate.swift       # Menu bar, accessibility permission guidance, and polling
├── EventTapManager.swift   # CGEventTap + keyboard state machine (core interaction logic)
├── AppSwitcherPanel.swift  # Cmd+Tab icon panel + window list (multi-screen)
├── SwitchPanel.swift       # Cmd+` window list panel (multi-screen)
├── WindowListService.swift # Window enumeration: CGWindowList z-order + AX titles/references
├── WindowActivator.swift   # Window activation: minimize/restore → AXRaise → activate
├── ListScrolling.swift     # Continuous list-scrolling controller + wheel response container
├── AXHelpers.swift         # Swift wrapper around AX APIs + private symbol isolation
├── UpdaterManager.swift    # Auto-update: Sparkle wrapper, mirror fallback, update UI activation
├── UpdateMenuState.swift   # Update menu state machine (checking / up to date / available)
├── Shortcut.swift          # Configurable trigger keys: model, matching, validation, storage
├── ShortcutRecorderView.swift      # Shortcut recording session + recorder control
├── SettingsWindowController.swift  # Settings window (behavior / updates / general / shortcuts)
├── LoginItemManager.swift  # Launch at login (SMAppService)
└── Theme.swift             # Global panel appearance settings

License

GPL-3.0 — any project that uses or modifies this software must also remain open source under GPL-3.0. Third-party: Sparkle (MIT; license text ships in ThirdPartyLicenses/Sparkle.txt).