Facebook has released an update to its iPhone and iPod touch app, bringing support for iOS 4 Fast App Switching. The update also provides high-resolution icons for the iPhone 4 Retina display, Korean and Russian localizations and minor bug fixes. Facebook released an update last week on the same day that iOS 4 was released, however this prior update was notably missing any features related to iOS 4 itself, focusing instead on adding support for video playback and other integration features. This latest update focuses primarily on iOS 4 and iPhone 4 compatibility. Facebook 3.1.4 is available from the App Store as a free download.