I\'m new to using the Facebook SDK and I wondered how detect when the user deletes the app from his Facebook account. Currently if we delete the app, and we want to post som
http://developers.facebook.com/docs/authentication/#app-deauthorization
App Deauthorization
When a user of your app removes it in the App Dashboard or blocks the app in the News Feed, your app can be notified by specifying a Deauthorize Callback URL in the Developer App. During app removal we will send an HTTP POST request containing a single parameter, signed_request, which contains the user id (UID) of the user that just removed your app. You will not receive an user access token in this request and all existing user access tokens will be automatically expired.