Combine Hollywood's hottest host with America's longest running weekend countdown and you've got American Top 40 with Ryan Seacrest. nnEvery week, from the heart of Hollywood, Ryan counts down from Number 40 to the hottest hit in America. AT40 brings you the best of music and entertainment, with news and gossip you'll hear nowhere else. nnGet the AT40 Weekend Chart in the palm of your hand.Send a song request, email the show or listen to the interviews with all of your favorite artists on the go and on demand.Plus, 247 access to the exclusive American Top 40 iheartradio stream.nnThe American Top 40 app is optimized for users of iOS 4.2 and above.It is best experienced on iPhone 3GS, iPhone 4 and the latest generation of iPod Touch devices.