After much speculation, Twitter Music finally launched as an iOS app.It's also available on the web too, but you'll be disappointed if you want it on your Android phone. That app is still some time off. It is coming, just not quite yet. So we're talking to just iPhone owners. The app works on iPad, but isn't formatted for it, hopefully a version for Apple's tablet will arrive down the line too.But if you have an iPhone, go get it, as the app is free and is really quite good. Once downloaded, you'll get the option of hooking up with one of your Twitter accounts, as well as Spotify or Rdio if you have them. If not, music will be played via Soundcloud or you will be directed to previews on iTunes.Talking of music, there are four screens for music discovery, based on the Twitter's taste and the friends you follow. That's Suggested, #NowPlaying, Popular, and Emerging. #NowPlaying is largely dependent on using the #nowplaying hashtag, so make sure you get plenty of use out of that if you want your taste to have an impact.Click on one of the selections in this lists to hear the music, it's that simple!Over time it could be a winner and it could also 'break' new acts if it works as it should. Time will tell. The UK is one of the first places to get Twitter Music, so get in now to be a pioneer of the service.