Facebook has recently change the way you manage apps by removing the App profile page completely. As I needed to add a newly created Facebook app to a Facebook page, the conventional way of doing this was no longer available.
However I’ve discovered through research that you can do so as long as you know the Facebook App ID and the URL of the App’s canvas URL.
Once you have those, simply enter this into your browser:
https://www.facebook.com/dialog/pagetab?app_id=YOUR_APP_ID&next=YOUR_URL
Don’t forget to replace ‘YOUR_APP_ID’ with your Facebook App ID and ‘YOUR_URL’ with the App’s Canvas URL. You can obtain these two values via http://developers.facebook.com/apps and selecting the desire app from your list of existing applications.