Natively login to facebook using the device's native facebook app credentials. 

• Login and Logout using simple actions
• Access the full breath of Facebook's GraphAPI
• Add more permissions for your app to get the level of clearance you need

NOTE: some assembly required (you know, facebook app setup and such...)

NOTE2: The more permissions you request, the more clearance you will need from Facebook's Login Review procedures (can be manual, depending on the type of permissions)