from my Android app, I would like to open a link to a Facebook profile in the official Facebook app (if the app is installed, of course). For iPhone, there exists the fb:// URL scheme, but trying the
In the facebook developers console for your app, go to App Review-> Permissions and Features. Set the public_profile and email to have advanced access. This will allow all facebook users to have access and these two settings are auto granted. Ensure the Access Level indicates Advanced Access