Urban Apps has released a major update to its Ambiance “environment enhancer” app for iPhone and iPod touch devices. Ambiance 3.0 is a complete rewrite of the application to support iOS4 and the coming iPhone 4. New features include High Definition sound images to support the new Retina Display on the iPhone 4, background audio support to allow ambient sounds to continue playing while using other applications, multiple customized alarms and alarm themes and support for downloading Ambiance sound updates in the background on iOS 4. The rewritten version also includes a completely revamped user interface to provide easier navigation. Ambiance 3.0 is available from the App Store for $3 and is a free update for existing users.