Sonos is releasing an Android version of the controler for its wireless music system today. The company, which allows users to listen to their downloaded music or to subscriptions on streaming services from Pandora to Spotify to Rdio, says it doubled in revenue last year and does 60% of its business outside the United States. One Sonos S5 unit retails for $400 for single room. I've been testing out two review units for the past few weeks and am really enjoying them.

I didn't know what the point of the Sonos was - until I had it in my house and under the control of my iPhone. Sonos co-founder Tom Cullen says that's a common experience.

"The iPhone made this business grow," Cullen says. "We've had a lot of products we've introduced to change the growth rate of this company and there's nothing like the iPhone that's done it. We released that in October '08 and saw a 15% uptick in a week. We expect the Android to do the same."

In addition to the standard Sonos options, the Android controler will allow users to search for music by voice. Cullen says that even when music is playing loudly, the Android voice recognition is effective.

What does the future hold for Sonos? Cullen says that getting costs down is key to the company's growth and that sounds about right - it would be great to be able to outfit rooms at less than $400 a pop. Logitech makes a wireless speaker system for under $100, but it doesn't appear to offer the software, user experience or audio quality that Sonos does.

Sonos raised $25 million in venture capital from Index Ventures last year, part of a big increase in investment across the music technology industry last year.

Internet music is what Sonos serves today, but the company aims to grow broader in its feature set inthe future.

"The S5 [model] is a smart speaker," Cullen says. "We expect that in the future, all speakers will have power and a brain. They will work one way for movie sound, another way for music. You'll take your smart phone and connect to any smart feature. We are a sound company and we'll cover every part of sound in the home."