NEW YORK (AP) - A digital radio service and changes to the software behind iPhones and iPads are among the features expected Monday as Apple opens its annual conference for software developers in San Francisco. Apple is expected to unveil a simplified look to iOS, the software that runs iPhones and iPads. If the speculation is correct, it would be the most radical design change since the iPhone made its debut in 2007. The alterations, however, could alienate long-time users accustomed to the existing look and feel. Although CEO Tim Cook has said people shouldn't expect new products until the fall, Apple could preview what those products will do in unveiling new services and features. Apple also is expected to debut a streaming music service dubbed iRadio. Apple's Worldwide Developers Conference runs through Friday.