I think the best way to have that API would have been to provide an app-specific link with an optional (or maybe even required) second parameter to a fallback l

I think the best way to have that API would have been to provide an app-specific link with an optional (or maybe even required) second parameter to a fallback link to the website for the same action. Let's say your app has a "share to FB" button, you'd poke the iOS Api by calling a method and passing both the facebook://shareSomething URI and the http://www.facebook.com/?sharestuff http://www.facebook.com/?sharestuff URI as a second parameter in case the app-specific URI is not handled by the device.