Napster now has an iPhone app, allowing subscribers to stream songs to their mobile device. Like the other streaming services, it offers streaming access to its full catalog, cache songs on the device, create playlists and adds an automix feature that builds a customized playlist based on a single song “seed.” And like those other services, the Napster app is free, but requires a $10 monthly Mobile Access subscription to use.

Napster’s pretty late to the iPhone party, but that’s by design. Before he left the company this January, former Napster CEO Chris Gorog said the company would not offer an iPhone app because the rates labels were charging for mobile access to streaming music was too high. Labels charge more for mobile streaming than they do for streaming to a PC because they feel it is a potential replacement for buying tracks.

Napster instead offered a mobile version of its online service, meaning interested users had to navigate to the mobile site via their phone’s browser rather than simply launch an app to access it directly.

Labels however have softened their rates for mobile access. It’s still more expensive than accessing music via the computer though, (online-only rates to customers are generally $5 a month, rising to $10 a month to include mobile access).

Best Buy acquired Napster for $121 million in 2008.