Launcher
The launcher is an application that allows players to access Toontown Rewritten via the account server and authentication server after entering their account credentials. It can be downloaded by visiting the "Play" page of Toontown Rewritten's website. The current look of the launcher depicts Doctor Surlee in his lab gazing at the monitor while holding a pencil and clipboard, with a large chalkboard displaying the news from behind.
macOS
Unlike Windows and Linux, the macOS launcher contains a built-in Cog Invasion tracker that actively updates whenever an invasion is present in Toontown. The tracker can be viewed by opening the launcher and selecting "View" then "Show Invasions" from the macOS menu bar.