From the Internet to find some of the statements, is to add uifilesharingenabled to the app's plist configuration file, I looked back at the Apple official website plist key Value Description document, also said.
But actually open the plist file directly through Xcode and don't see it. Later found "application supports ITunes file sharing", and set the value of this item to Yes, found to be available.
Back to the source of the way to open the Plist file, found that there is indeed a "uifilesharingenabled" this item. After running the app on the real machine and viewing it on itunes, it turns out that you can share the file with the app, upload a local folder to it, and then view it through Iexplorer and find that the final folder is uploaded to the documents directory in the app directory on your device.
Add itunes file sharing support to your app