I have already implemented facebook login/signup on a site, using a combination of the Javascript and PHP SDKs. I remember that the review process took about a day or two. That was for a brand new site.
Now I need to add the same functionality to another site that exists and currently has hundreds of visitors per day. I have already implemented the changes and it works fine in sandbox mode but here's my question:
When I upload the new code, and until the facebook app is reviewed and accepted, there will be two buttons "login with facebook" and "signup with facebook" that will not be operational. This might confuse some users and have a negative impact on the perceived credibility of the site. These buttons need to be on the same screen next to the standard email/password forms.
Is there something I can do about this? Can I hide the buttons from the general population until the app is reviewed? Is there some specific GET parameter that the testers send to the server to know that a request is for review purposes? What do other web developers do in this situation?