You can continue to use URL schemes when you build your app for iOS 9 and you want to call URL schemes, you will now need to declare them in your apps Info.plist. There is a new key, LSApplicationQueriesSchemes, and here you will need to add the list of schemes you want to are canOpenURL on.

<key>LSApplicationQueriesSchemes</key>
<array>
<string>fbauth2</string>
</array>