Iphone app sharing file with iTunes problem

Somebody please help me out. This problem is killing me.

I went through tones of documents and posts. All seems to suggest that simply add a UIFileSharing key into info.plist and set boolean value to YES, files in App's Documents folder 开发者_如何学C(not sub-folder, I know) will show up in iTunes.

However my problem is that I don't have an iPhone, so I really have no clue about what exactly the behaviors of both iPhone or iTunes will be when try to verify this file sharing thing. And what is the right way to verify this. So when my client try to verify this off my watch (we are on different sides of earth), he keeps reporting back that file sharing feature not work. It is certain that file is properly stored under Documents folder.

In the last attempt, he claimed that he can see the app but not files.

I would like to know the following things, so I can guide him through this and end this pain:

1. Is it really plain and simple like add one key, no changes to code needed? Or did I miss something?
2. Are there any special requirements for building (like, only work for release build?), deploying?
3. What will really happen when plug the iPhone into the computer and sync with iTunes? Will the app show up in the Apps tab anyway, or only show up if file sharing feature are enabled correctly?

Thank you all.

Is it really plain and simple like add one key, no changes to code needed? Or did I miss something?

Yes

Are there any special requirements for building (like, only work for release build?), deploying?

No

What will really happen when plug the iPhone into the computer and sync with iTunes? Will the app show up in the Apps tab anyway, or only show up if file sharing feature are enabled correctly?

It will show up in the app view (on top) all the times. But you will only see them in the file sharing area if you have an app with enabled filesharing.

File sharing is only available on iPhone OS 4 onwards and iPad 3.2 Make sure your client has iOS4 or later.