App Detective

App Detective identifies how macOS apps are built: their UI framework, language, renderer, and updater.

Install

Homebrew

brew tap hewigovens/tap
brew install --cask app-detective

Command-line tool

App Detective ships with appdetective, a CLI for analyzing a single .app bundle.

Install it from inside the app: App Detective → Install Command Line Tool… symlinks appdetective into ~/.local/bin/. If ~/.local/bin isn't on your PATH, the install dialog tells you the line to add.

You can also start the app directly on a folder:

open -a "App Detective" --args --scan-folder /Applications

$ appdetective /Applications/Visual\ Studio\ Code.app
App:        Visual Studio Code.app
Path:       /Applications/Visual Studio Code.app
Bundle ID:  com.microsoft.VSCode
Version:    1.142.0 (1.142.0)
Size:       900 MB
Category:   Developer Tools
UI:         Electron
Updater:    Squirrel

Use --json for machine-readable output (handy for scripts and agents), and --explain to see the evidence behind each trait:

$ appdetective --json /System/Applications/Calculator.app
{
  "build" : "225",
  "bundleId" : "com.apple.calculator",
  "category" : "Other",
  "name" : "Calculator.app",
  "path" : "/System/Applications/Calculator.app",
  "possibleTraits" : [ ],
  "sizeBytes" : 4954666,
  "sizeHuman" : "5 MB",
  "traits" : {
    "language" : [ "Swift" ],
    "ui" : [ "SwiftUI" ]
  },
  "version" : "12.0"
}

What It Detects

Each app gets a list of traits, grouped by kind.

UI Frameworks

• Native: SwiftUI, AppKit, UIKit (iOS apps on Apple silicon), Catalyst
• Web runtimes: Electron, Chromium Embedded Framework, Microsoft Edge
• Cross-platform: Flutter, React Native, Qt, GTK, wxWidgets, Compose Multiplatform, Avalonia, Xamarin/MAUI, Xojo
• Rust and Go: Tauri, GPUI, Iced, egui, Slint, Wails, Fyne
• Runtimes: Java, Python
• Game engines: Unity, Unreal Engine

Languages

• Swift, Objective-C, Rust, Go, found in the app's executable, its own frameworks, and its extensions

Renderers

• wgpu, for apps that draw their own UI on the GPU

Updaters

• Sparkle, Squirrel (Electron), Tauri Updater, App Store

Contributing

See CONTRIBUTING.md.

License

BSL 1.1 — free to use, modify, and redistribute; paid app store distribution requires permission. Converts to Apache-2.0 on 2030-03-23. See LICENSE.