Question: During my app review I received the following:
"17.2: Apps that require users to share personal information, such as email address and date of birth, in order to function will be rejected

Specifically, your app uses Facebook login for authentication purposes only, but does not include account-based features offered by that site, which is not allowed on the App Store.

In order for Facebook to be the only authentication mechanism available, your app must include significant account-specific functionality from Facebook. Pulling profile information, or sharing are not sufficient account-based features for Facebook to be the only authentication mechanism available. 

It would be appropriate to implement your own authentication mechanism, or implement significant account-specific functionality from Facebook."

**My Question:**
What are some examples of "significant account-specific functionality from Facebook"?

Would allowing users to choose pictures from their Facebook for their profile, or displaying mutual friends using my app pass this requirement?

**\*Note:** I'm building a dating app kind of like Tinder

Thanks!

Answer: 
There is certainly a bit of gray area here. But the question you need to ask yourself is, "how can I make my app useful to users who can't login via Facebook?"

If the answer really is "I can't" then your app does indeed require Facebook authentication. It's not useful to anyone who does not have a Facebook account. A contrived example of this could be, for example, "Facebook Group Finder", an app that scans your interests on Facebook and suggests Facebook groups for you to join. If you don't have a Facebook account, then this app can be of no use to you.

Clearly, Apple however believes that your app does not fall into that category of apps. It has useful functionality that should not require a Facebook account to use. According to Apple's review notes, it sounds like your app just requires Facebook credentials so that a user can log in, and does not use any Facebook APIs or information from Facebook beyond that point (or perhaps, it uses them, but using them is not crucial to its operation).

If this is the case, it sounds like you could replace the Facebook account requirement with a requirement for the user to create an account on your website (or whatever) instead, and not really have any loss of functionality compared to a Facebook login. Apple is asking you to add that as a login alternative.

Allowing users to choose pictures from their Facebook profile definitely wouldn't satisfy Apple, since Facebook is not by far the world's only source of pictures. Displaying mutual friends, this probably also wouldn't do it, but it's more of a gray area. It seems like you could just leave the "mutual friends" part out of your app for non-Facebook users.
If you are going to use Facebook log in, apple wants you to use significant account-specific functionality. This means that you should use things from Facebook like user interest or friend list. Using the user name profile pictures are not considered account specific functionality. Apple is saying if you are not using these information then you are not supposed to use Facebook authentication. You have 2 solutions here: 

1. Use the significant account-specific functionality from Facebook ex. interests of friend list.
2. Apple will accept the use Facebook log in without significant account-specific functionality if you also add your own login and password.

Tender app is using only Facebook log in and it is not rejected because tinder uses your friends list and interest from Facebook. If you can point to apple how you are using information like this they will accept your app.

I am sure of this information because I got it from apple review team member today!