When Spotify launched its first wave of apps in November 2011, it made clear its goal to become "the OS of music," a place to find, browse, and listen to million of songs. The apps have thus far been a success, amassing over 13.1 million hours of usage since they launched. Today, Spotify is set to launch a second wave of apps to help users find music to listen to, such as TweetVine, Def Jam, Filtr, Matador Records, Domino, Classify, and a handful more.

Each app provides a different take on music discovery and sharing, and some even let you dig deep into the history of storied record labels. TweetVine, for example, scrapes Twitter for every "#NowPlaying" mention so you can see what people you aren't friends with are listening to. Def Jam features curated content from the label's rich 26-year history. Filtr creates playlists based on the tastes of your Facebook friends, and Classify lets you browse the classical music genre by composer, era, and even by mood. Another highlight is the Hot Or Not app, which lets users pick which of two songs is hottest. The apps are available today inside the Spotify desktop app's App Finder section, and are all offered free of charge.

  • Classify: classical music organized by genre, instrument, mood, composer, and more
  • The Complete Collection: 150 album booklets available, with details about who wrote and produced your favorite pop songs
  • Def Jam: 26 years of Dem Jam recordings and information in one app
  • Digster: match Digster playlists to your listening history and Facebook likes, then turn on full screen mode for partying
  • Domino: highlights artists throughout Domino's storied history
  • Filtr: builds playlists based on the tastes of your Facebook friends
  • Hot or Not: decide which of two songs is hot or not, then ascend the rankings as you mark more songs correctly
  • The Legacy Of: a "visual feast" containing history's most acclaimed musicians
  • Matador Records: an interactive guide to the New York music label, including all of its albums and music
  • [PIAS]: experience new albums and curated playlists from the indie label
  • TweetVine: born from a London hackathon, TweetVine scans Twitter for #NowPlaying hashtags to show you what people you're not friends with are listening to
  • The Warner Sound: the complete Warner music experience, which includes Green Day, Cee Lo Green, Wiz Khalifa, and Fun

It's interesting to see apps from prestigious labels like Warner alongside the Hot Or Not app, but there's still nothing on the same level as Pitchfork or Rolling Stone in this wave of apps. And despite Spotify's impressive (and peerless) app selection, it's been months and the company still hasn't brought a single third party app to the Spotify mobile app. If the 10-million-user strong music service wants these apps to take off, it'll need to engage users on their mobile devices — where more and more music is consumed each day.