Phono is a jQuery based VoIP SIP phone that runs in the browser. When the red button is clicked, it places a SIP call into a Tropo application using the WebAPI. The Tropo application is written in Node.JS and uses the Tropo-WebAPI and Express NPM modules. The Tropo app first asks the caller to say or enter a phone number. The phone number is posted back to the Tropo app (/answer) where a transfer response is returned to the Tropo cloud.