As you should know, Facebook’s Application Directory is a place that list out all the applications available in the Facebook Realm.
Once after we finished our applications, we can submit it for free as long as we get the necessary number of MAU (Monthly Active Users).
However, no more new applications is allowed! This is because the “submit to app directory” function is not working at the moment. This had been reported already in Bugzilla as App directory submission is broken.