Apple on Monday unveiled its hotly anticipated iTunes Radio Service, as the iconic maker of the iPhone moved to challenge streaming music operators like Pandora and Spotify. The free Internet radio service features over 200 stations \"and an incredible catalog of music from the iTunes Store,\" Apple said in a statement as it opened its annual developers conference in San Francisco. The ad-supported free music service is set to launch later this year and \"offers music fans access to thousands of new songs every week, as well as serving up exclusive music from new and popular artists before you hear them anywhere else,\" an Apple statement said. The service will be integrated with Apple\'s personal voice-assistant software program Siri, so users will be able to find out \"Who plays that song?\" or ask the program to \"Play more like this.\" \"iTunes Radio is an incredible way to listen to personalized radio stations which have been created just for you,\" said Eddy Cue, Apple\'s senior vice president of Internet software and services. \"It\'s the music you love most and the music you\'re going to love, and you can easily buy it from the iTunes Store with just one click.\"