What do you do to improve a service with over 50 million active users? Why, totally revamp it of course. It sounds crazy, but that’s exactly what TuneIn, an audio service that lets you listen to podcasts and radio stations from around the world, did. Before, TuneIn was more like a directory with a search engine. Now, it’s a full-blown audio network, which CEO John Donham says is the first of its kind.

Streaming radio aggregator TuneIn relaunched its mobile apps and website Wednesday, introducing a Twitter-like follower model and adding new ways for podcasters, radio staions and brands to reach an audience. The new TuneIn allows users to follow individual shows like This American Live, radio stations like KCRW, broadcasters like the BBC and even musical genres like Alternative Rock. Users also get a profile and are able to follow their Facebook friends or contacts from their phone’s address book. The result looks a lot like Twitter or Facebook, complete with a news feed that lists new shows, and so-called echoes, which TuneIn CEO John Donham called “essentially our version of a tweet” during a demo earlier this week.