What information does it require users to give? Does it actually ask them for it, or is it that you can just see their Facebook profile. As long as people don't think it's too personal, I'd like to have it as it would prevent users from appearing "faceless."
Does the app have to be complex, or can it just be any old app?
The box pops up saying that users agree to allow (your wiki) to know, "name, profile picture, gender, networks, user ID, list of friends, and any other information I've shared with everyone."
You aren't creating an app. You are just registering with Facebook.https://developers.facebook.com/docs/guides/web/
Facebook helps you simplify and enhance user registration and sign-in by using Facebook as your login system. Users no longer need to fill in yet another registration form or remember another username and password to use your site. As long as the user is signed into Facebook, they are automatically signed into your site as well. Using Facebook for login provides you with all the information you need to create a social, personalized experience from the moment the user visits your site in their browser.