From my iOS-App I would like to disable sharing to Apps like Tumblr or Instapaper. My instance of UIActivityViewController has the property excludedActivityTypes, but what exactly do I put into this array?
For example, when Tumblr-sharing succeeds, the activity name, taken from completionWithItemsHandler is com.tumblr.tumblr.Share-With-Tumblr. But adding this string to excludedActivityTypes doesn't remove Tumblr from the list of choices.