The Facebook Graph API documentation indicates that there is an application element of the post object:
http://developers.facebook.com/docs/reference/api/post/
But we often don’t see an application element at all. When that happens, does it mean that the post was created through a browser on the Facebook web site?
Here’s an example:
https://graph.facebook.com/7976226799_10151201757386800?access_token=XXXX
Yes. That’s what it means. If there wasn’t an Application it means it was made with Facebook’s own interface.