Our app can deal with say Pages files as an example and needs to both hand off files to other applications as well as receive files from other applications.
So we edit the plist CFBundleDocumentTypes to say that we can deal with Pages files. ('Default') mode.
When the user wants to send a .pages file onto another application (Likely the Pages app) then we call UIDocumentInteractionController.
The UIDocumentInteractionController (too) faithfully lists all applications that can deal with .pages files, and WE are on the list. I think that's confusing to the user, why would I use the UIDocumentInteractionController to hand a file off to US? How do we rid ourselves from the list?