What it does
Every menu, window title, setting, and status message is translated into 14 languages and follows your system language at launch.
How it works
Strings live in a String Catalog (`Localizable.xcstrings`). At build time, Xcode emits per-locale `.lproj/Localizable.strings`. Arabic flips the layout right-to-left automatically. Override the language at launch with `open -n -a 'Shake It On.app' --args -AppleLanguages '("ar")'`.
Where to find it
macOS System Settings → Language & Region.
When to use it
It's automatic. Want to verify it locally? Use the launch-arg trick above.