BusKill App is a cross-platform security tool that functions as a laptop kill cord, designed to protect your device when it's physically separated from you. The application works by monitoring a connected USB device and triggering predefined security actions when the USB connection is broken. By default, it locks your screen when the USB device is removed, but it can be configured for other actions. BusKill App offers both command-line interface (CLI) and graphical user interface (GUI) options, making it accessible to both technical and non-technical users. It's compatible with multiple operating systems including Linux, Windows, MacOS, and QubesOS. The tool addresses a specific physical security threat scenario: when an adversary attempts to steal or gain unauthorized access to your laptop while it's in use. By creating a physical tether between you and your device, BusKill provides an automated response to potential theft or unauthorized physical access. Users can either purchase a pre-made BusKill cable or build their own using instructions available on the official website. The application itself is the software component that monitors the USB connection and executes the security response when triggered.