Dual

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Clone any macOS app into an independent copy with its own name, bundle identifier, and identity.

Dual copies a selected .app bundle to a new destination, rewrites its display name and bundle identifier, and re-signs it so the clone launches and runs independently of the original — useful for testing, isolated sessions, or running multiple accounts of the same app side by side.

Features

• Clone a selected .app bundle into a new destination with its own display name and bundle identifier.
• Drag and drop any .app, or quick-pick common apps found in /Applications and ~/Applications.
• Rename helper apps for apps that ship helper bundles, so the clone stays launchable.
• Apply app-specific compatibility fixes and give Electron clones a separate user-data directory on every launch, including launches from Finder.
• Optionally add a badge icon to the clone so it's visually distinguishable from the original.
• Clear previous clone data before creating a new copy, with optional deeper isolation cleanup.
• Remove stale quarantine attributes and re-sign the cloned bundle.
• Request administrator privileges when the destination requires elevated access.
• Track existing clones and show their source/up-to-date status, with a live log panel and a Finder reveal action after success.
• Import an existing clone by selecting its .app; match its original under /Applications when possible, otherwise prompt for the source.
• Localized UI in English and Simplified Chinese.

Requirements

• macOS 12.0 (Monterey) or later.
• Apple Silicon and Intel Macs are both supported.

Installation

Homebrew

Install Dual from the helson-lin/tap Homebrew tap:

brew tap helson-lin/tap
brew install --cask helson-lin/tap/dual

Download

Download the latest .dmg for your Mac from GitHub Releases, open it, then drag Dual into Applications.

Usage

1. Drag an .app bundle onto the drop zone, or quick-pick one of the suggested apps from /Applications or ~/Applications.
2. In the clone panel, set the clone's display name and bundle identifier (Dual suggests defaults based on the source app).
3. Choose a destination directory, or keep the default /Applications/Cloned.
4. Optionally enable the clone badge icon and clearing prior clone data, then start the clone.
5. When cloning finishes, use the reveal action to open the new copy in Finder.

Compatibility

Compatibility fixes have been verified for the apps below. Other apps may clone successfully too — please open an issue or PR with your results to help grow this table.

App	Logo	Work
WeChat		✅
QQ		✅
WeChat Business		✅
Ghostty		✅
Kaku		✅
IINA		✅
Telegram		✅
Discord		✅

How It Works

The UI is SwiftUI; the actual cloning runs through an AppCloner pipeline:

1. Read the source app's bundle identifier and detect an app-specific compatibility profile (for example Telegram or Discord).
2. Reject the request if the new bundle identifier matches the source's.
3. Generate a badge icon for the clone, if enabled.
4. Clear previous clone data (and deeper per-app isolation data, if needed) before copying.
5. Copy the app bundle with ditto, replacing any existing destination.
6. Rewrite Info.plist with the new display name and bundle identifier, and install the badge icon.
7. Apply app-specific patches (Telegram identity label, Discord user-data path) when needed.
8. Rename Electron helpers and the main executable; for Electron clones, install a launcher that passes a per-bundle-ID --user-data-dir before re-signing.
9. Clear extended attributes and re-sign the cloned bundle with codesign.

Development

Building locally requires Xcode with the macOS 12.0 SDK or later.

open Dual.xcodeproj

To produce a signed, notarized, packaged build the same way CI does, use scripts/build-release.sh (set ARCH to arm64 or x86_64):

ARCH=arm64 scripts/build-release.sh

Other scripts in scripts/:

Script	Purpose
build-release.sh	Builds, signs, notarizes, and packages a release zip/dmg.
configure-signing-secrets.sh	Interactively uploads Apple signing/notarization secrets to GitHub.
configure-update-secrets.sh	Interactively generates and uploads Sparkle EdDSA update keys.
re-sign-local.sh	Ad-hoc re-signs a local .app copy for development testing.
remove-quarantine.sh	Strips the com.apple.quarantine extended attribute from an .app.
sync-homebrew-tap.sh	Publishes an updated cask to the helson-lin/homebrew-tap repo.

Release & Distribution

The Build macOS GitHub Actions workflow (.github/workflows/build-macos.yml) builds Intel and Apple Silicon variants, signs them with a Developer ID certificate, and notarizes them with notarytool via scripts/build-release.sh. On a tagged push (or a manual dispatch with a release tag) it also:

• Generates a Sparkle EdDSA-signed appcast for each architecture, so the app can check for and install updates in place.
• Publishes the signed zip/dmg artifacts and appcasts to a GitHub Release.
• Syncs the helson-lin/homebrew-tap cask (scripts/sync-homebrew-tap.sh) with the new version, build number, and checksums.

Run scripts/configure-signing-secrets.sh to set up the Apple signing/notarization secrets, and scripts/configure-update-secrets.sh to set up the Sparkle update keys, before the workflow can produce a signed release.

Project Structure

Dual/
├── Dual/                      # SwiftUI app source (views, AppCloner pipeline, localization)
├── Dual.xcodeproj/            # Xcode project configuration
├── scripts/                   # Build, signing, and maintenance scripts
├── .github/workflows/         # GitHub Actions build & release workflow
├── assets/                    # README screenshot(s)
├── background.png             # DMG installer background art
└── LICENSE                    # GPLv3 + Commons Clause license text

Troubleshooting

Broken or stale Homebrew cask. If a previous install was removed manually, or the cask record no longer matches the installed app, force-remove it before reinstalling:

brew uninstall --cask --force helson-lin/tap/dual
brew install --cask helson-lin/tap/dual

Gatekeeper blocks the app on first launch. Releases are signed and notarized, so this is usually a leftover quarantine flag from how the app was copied. Clear it with scripts/remove-quarantine.sh (defaults to /Applications/Dual.app), which strips the com.apple.quarantine attribute only — it does not replace signing or notarization:

scripts/remove-quarantine.sh /Applications/Dual.app

If it's still blocked, right-click the app in Finder and choose Open, or allow it in System Settings → Privacy & Security.

Contributing

Issues and pull requests are welcome. The Compatibility table is community-driven — if you've cloned an app not listed there, please share your results.

License

Dual is licensed under GNU GPLv3 with additional Commons Clause terms. Personal, non-commercial use only unless the copyright holder grants explicit written permission. Derivative works must retain the same license terms. See LICENSE for the complete terms.