Spotify unveiled a major change in their service as they integrate apps into their long term outlook.

The added app support will enable third-party functionality such as music reviews, lyrics, nearby concert information and ticket purchasing, which can be accessed via the streaming music service’s PC and Mac software.  App development will also be opened up freely to developers but before the apps are released publicly, Spotify will test and approve each app.  Today’s announcement also signifies the start of Spotify’s role as an “authentication layer” between labels, developers and users.

The Spotify apps will be free and available to all Spotify users, whether paying or ad-supported subscribers.  Spotify claims that they now have over 2.5 million paying subscribers and they correlate the subscriber increase with their Facebook deal.

Additionally, Spotify is building a world-class engineering team and aspiring to provide a productive and inspiring environment so that their service can be made available to everyone around the world.

Spotify is looking to hire a Lead Architect that will charge architecture and software-design functions for their newly formed New York engineering department.  The Lead Architect will participate in a four person global team which will work directly with their CTO  and lead the architecture and technical vision of the company.

Back in September 2010, Spotify and Sonos, manufacturer of multi-zone digital music system, announced their partnership which brought Spotify to every room in every household via the award-winning Sonos Multi-Room Music System.  And now, their partnership reached another level as Sonos pushed out their latest free software update, Sonos software 3.6, which includes support for Android tablets, Sonos users in U.S. and Canada can now tune in for free to 150 expert-programmed stations and create their own on Slacker Radio, enhanced Sonos Spotify experience with an added support for the AAC+ music format, and the Introduction of Sonos Labs, which provides a place for users to experiment with up-and-coming music services.