The Social Login section gives you three options to log in:
In this field, you have to mention your App ID and Application name. For this, you initially have to Setup facebook login for mobile App. Once you have configured your ID and name enter the details in the respective fields.
To set uplinkedinlogin for the mobile app, you have to register with the Linkedin developer. After you receive the Application ID fill from the App, you have to mention your App id in the field after you are registered with the Linkedin developer.