title: Facebook oauth unified scoped id across apps in same business
body: <p>I have two facebook apps in the same business. 
  I want to get same scoped ids for both apps when users are logging in (because I use the same database).
  I've read the facebook upgrade guide, but I don't get how to use the token_for_business to get same id when the user is logged.
  Graph api returns different tokens for business for every app (which is strange).</p>
  
  <p>The only useful thing so far is the /me/ids_for_business call to get list of the user scoped IDs for every busines..but it only returns them if they were logged at least 1 time..</p>
  
  <p>My second app is new and if user logs in to it (without logging in to the first app) I can't get his first app ID to store and use it.</p>
  
  <p>Thanks</p>