European startup Soundcloud is killing it right now, with over 3million users the voice and music sharing app is becoming the YouTube for all things sound. In their new app they’ve  partnered with Foursquare to allow you to check in your sounds to places and share it on Foursquare as demonstrated in the video above. I caught up with founder Alexander Ljung to talk who he’s grown the startup from concept to growing company in a few years.