A radio app that lets you listen to the radio has pretty much met its essential responsibilities. If it recommends more music that you'd probably like based on what you've listened to so far, it's doing the job of digital radio in 2010. But the iPad app from Radio.com, a product of CBS Interactive Music Group, stands out for its above-and-beyonds, such as seamlessly serving up content from radio stations' websites. Ditto for the stations' Twitter feeds.
We also like browsing stations -- by genre, city, or provider, whether terrestrial or online -- while listening to another. When the commercial break comes, we've already got a new radio station ready for us (sorry, advertisers). Copious info and photo galleries on the artists at hand round out a package that stands way out from the competition.