Sadly the one that runs as a Chrome app doesn't work with PuckJS in Windows 10 yet - we're still waiting on Google's Web Bluetooth implementation for Windows.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Are you using the Web IDE that you download and install from here? http://www.espruino.com/Web+IDE
Sadly the one that runs as a Chrome app doesn't work with PuckJS in Windows 10 yet - we're still waiting on Google's Web Bluetooth implementation for Windows.