Slacker is a popular streaming Internet radio service that, until recently, was accessible only through a computer or through one of the company's standalone media players. Last spring Slacker announced it would branch out into the mobile space. It first released an application for the BlackBerry, and now there's a version available for the iPhone. This free download is better than Pandora for the iPhone in some ways, but we wish you could cache stations for offline listening, as you can on the BlackBerry.
Slacker Radio offers two account options, Basic and Plus. The Basic plan is free, but you can only skip six songs per station per hour, and every five songs or so you'll hear 30-second advertisements for upgrading to Slacker Radio Plus. While this is fairly noninstrusive, a $3.99 monthly Plus subscription eliminates advertisements. Even better, you can skip as many tracks as you want, and make unlimited song requests.
Slacker's interface is beautiful. A large portion of the iPhone's display displays album art, with the station name displayed at the top. Below is a Pause button, a Skip key with the number of available skips left, Love and Ban buttons, and a Settings tab. Also shown is the artist's name and the title of the current track playing. Clicking on the track name brings up album reviews and background information on the artist.
We quickly fired up the stations list and chose Top Hits. Skipping songs is as simple as dragging your finger across the screen; when you do this, album art for the next song floats up to the surface of the display. If you slowly pull your finger along the iPhone's screen, you can see what song is up next. A double tap on the screen will pause and resume playback.
Overall, Slacker's UI for the iPhone is cleaner and sleeker than Pandora's. While Pandora 2.0 has plenty of stations to choose from, they aren't as enticing as Slacker's recommended Top Hits or Top Stations. Instead, Pandora just offers stations by genre. Moreover, Slacker has a constantly updated Slacker Spotlight with a list of stations such as Obama and Jack Bauer (the latter of which plays Kiefer Sutherland's favorite artists).
With a full 3G connection, songs took about 5 seconds before beginning to play. On an hour-long train ride from Long Island to New York, we experienced just a few spots where the audio dropped out, but each time it came back within about 10 seconds. Songs sounded nearly as good as MP3s on our iPhone; we listened to Stevie Wonder's "Signed, Sealed, Delivered" and were able to hear his voice, as well as the background singers and instruments, perfectly.
Slacker for iPhone has a few downsides. Unlike the BlackBerry version or the browser-based Slacker player, you can't cache stations to the iPhone for offline playback, even if you have a Slacker Premium account. Worse, you can't leave the music playing while have other applications running. That's not Slacker's fault, though, it's because Apple only allows one application to run at a time on the iPhone. The BlackBerry version will run in the background, so you can check e-mail or browse the Web while you listen to tunes.
While we don't like Slacker's iPhone app as much as the one for the BlackBerry, the reasons have more to do with the limitations of the iPhone than anything else. Still, with its easy-to-use, beautiful interface and good audio quality, the free Slacker application is our top choice for streaming radio on the iPhone.