Smule has released an update to its Glee application for the iPhone, iPod touch and iPad. Updated for Season 2 of the popular TV series, Glee Karaoke introduces a global competition mode where users sing to compete with fellow Glee fans from around the world and complete individual singing missions to gain levels and win starburst points and gleeks. Glee Karaoke also provides personal voice coaching tips to improve singing skills as well as pitch…