Proxy, a San Francisco-based startup, wants to kill the key card and replace it with a mobile app that can access all sorts of devices. To start off, Proxy has launched a pilot for offices. A technician installs a maximum of two Bluetooth sensors (for the pilot), and from there an account manager can set up accounts for employees and rules. See Also: Who are the startups upgrading the auto industry? When walking towards the door, the Bluetooth sensor will automatically recognize an employee and unlock the door.