This app stores devices list at first start as default and stays alive during system uptime. It prevent system from shuting down if some non default device has been forgotten in pc. The main purpuse is to avoid of leaving usb storage devices in the office pc when going gome. Just set it to autostart and enjoy!
If you need to reset default list, kill the process, delete ShutdownNotifier.conf in the app's working dir and run it again.