Wrappers for Prime 31 IOS and Android FB Integration Uses 3.18 version of these plugins http://prime31.com/docs#androidSocial http://prime31.com/docs#iosSocial

AndroidFacebookManager.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;



#if UNITY_ANDROID
public class AndroidFacebookManager : IFacebookManager
{
    
	public event LoginSuccessHandler OnLoginSuccess;

	public event LoginFailedHandler OnLoginFailed;


	public bool supported {
		get {
			return true;
		}
	}

	public void init() {
		FacebookManager.sessionOpenedEvent += onInternalSessionOpened;
		FacebookManager.loginFailedEvent += onLoginFailedEvent;
		FacebookAndroid.init();
	}


	protected void onLoginFailedEvent(string obj) {
		if(OnLoginFailed != null){
			OnLoginFailed(obj);
		}
	}
	
	protected void onInternalSessionOpened() {
		if(OnLoginSuccess != null){
			OnLoginSuccess();
		}
	}

	public string getAppLaunchUrl() { // JSM - not supported via android bindings
		return null;
	}

	public bool isSessionValid() {
		return FacebookAndroid.isSessionValid();
	}

	public string getAccessToken() {
		return FacebookAndroid.getAccessToken();
	}

	public void graphRequest(string path, GraphResponseHandler complete){
		Facebook.instance.graphRequest(path, delegate(string respath, object result){complete(respath, result);});
	}


	

	public void login() {
		GameLog.debug("Facebook login");
		FacebookAndroid.login();
	}

	public void loginWithReadPermissions(string[] permissions) {
		GameLog.debug("Facebook login");
		FacebookAndroid.loginWithReadPermissions(permissions);
	}
	
}
#else

public class AndroidFacebookManager : MockFacebookManager
{

}
#endif

IFacebookManager.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public delegate void LoginSuccessHandler();
public delegate void LoginFailedHandler(string result);
public delegate void GraphResponseHandler(string path, object result);

/// <summary>
/// Interface for a platform specific facebook manager
/// </summary>
public interface IFacebookManager
{

    /// <summary>
	/// Occurs when player logs into facebook
	/// </summary>
	event LoginSuccessHandler OnLoginSuccess;

	/// <summary>
	/// Occurs when a login fails, likely due to cancelling
	/// </summary>
	event LoginFailedHandler OnLoginFailed;

	/// <summary>
	/// Gets a value indicating whether this <see cref="IFacebookManager"/> is supported on the current platform
	/// </summary>
	/// <value>
 	///   <c>true</c> if supported; otherwise, <c>false</c>.
	/// </value>
	bool supported { get; }

	/// <summary>
	/// Inits the underlying implementation
	/// </summary>
 	void init();

	/// <summary>
	/// Fetches the url which caused our runtime to launch, only available on certain platforms
	/// </summary>
	/// <returns></returns>
 	string getAppLaunchUrl();

	/// <summary>
	/// Determines whether the current session is valid
	/// </summary>
	/// <returns>
	///   <c>true</c> if [is session valid]; otherwise, <c>false</c>.
	/// </returns>
	bool isSessionValid();

	/// <summary>
	/// Gets the current access token.
	/// </summary>
	/// <returns></returns>
	string getAccessToken();

	/// <summary>
	/// Issues a graph request
	/// </summary>
	/// <param name="path">The path to request.</param>
	/// <param name="complete">Completion callback.</param>
	void graphRequest(string path, GraphResponseHandler complete);

	/// <summary>
	/// Attempts to log the current player in
	/// </summary>
	void login();

	/// <summary>
	/// Attempts to log the current player in the given permissions requested
	/// </summary>
	/// <param name="permissions">The permissions.</param>
	void loginWithReadPermissions(string[] permissions);
}

Initialization.cs

	if (Application.platform == RuntimePlatform.IPhonePlayer) {
		ServiceLocator.facebook = new IOSFacebookManager();
	}
	else if (Application.platform == RuntimePlatform.Android) {
		ServiceLocator.facebook = new AndroidFacebookManager();
	} else{
		ServiceLocator.facebook = new MockFacebookManager();
	}
	ServiceLocator.facebook.init();

IOSFacebookManager.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;



#if UNITY_IPHONE
public class IOSFacebookManager : IFacebookManager
{
    
	public event LoginSuccessHandler OnLoginSuccess;

	public event LoginFailedHandler OnLoginFailed;


	public bool supported {
		get {
			return true;
		}
	}

	public void init() {
		FacebookManager.sessionOpenedEvent += onInternalSessionOpened;
		FacebookManager.loginFailedEvent += onLoginFailedEvent;
		FacebookBinding.init();
	}


	protected void onLoginFailedEvent(string obj) {
		if(OnLoginFailed != null){
			OnLoginFailed(obj);
		}
	}
	
	protected void onInternalSessionOpened() {
		if(OnLoginSuccess != null){
			OnLoginSuccess();
		}
	}

	public string getAppLaunchUrl() {
		return FacebookBinding.getAppLaunchUrl();
	}

	public bool isSessionValid() {
		return FacebookBinding.isSessionValid();
	}

	public string getAccessToken() {
		return FacebookBinding.getAccessToken();
	}

	public void graphRequest(string path, GraphResponseHandler complete){
		Facebook.instance.graphRequest(path, delegate(string respath, object result){complete(respath, result);});
	}


	

	public void login() {
		GameLog.debug("Facebook login");
		FacebookBinding.login();
	}

	public void loginWithReadPermissions(string[] permissions) {
		GameLog.debug("Facebook login");
		FacebookBinding.loginWithReadPermissions(permissions);
	}
	
}
#else

public class IOSFacebookManager : MockFacebookManager
{

}
#endif

MockFacebookManager.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Prime31;
public class MockFacebookManager : IFacebookManager
{
    public event LoginSuccessHandler OnLoginSuccess;

	public event LoginFailedHandler OnLoginFailed;

	public bool supported {
		get {
			return false;
		}
	}


	public void graphRequest(string path, GraphResponseHandler complete) {
		GameLog.debug("Graph request for " + path);
	}

	public void init() {
		GameLog.debug("Facebook init");
	}

	public string getAppLaunchUrl() {
		return null;
	}

	public bool isSessionValid() {
		return true;
	}

	public string getAccessToken() {
		return null;
	}

	public void login() {
		GameLog.debug("Facebook login");
	}

	public void loginWithReadPermissions(string[] permissions) {
		GameLog.debug("Facebook login with read perms");
	}
}

SocialNetworkUser.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;

/// <summary>
/// Data bean for a social network user
/// </summary>
public class SocialNetworkUser
{

    /// <summary>
	/// Gets or sets the platform ID for this user
	/// </summary>
	/// <value>
	/// The platform ID.
	/// </value>
	public int PlatformID { get; set; }

	/// <summary>
	/// Gets or sets the platform user ID.
	/// </summary>
	/// <value>
	/// The platform user ID.
	/// </value>
	public string PlatformUserID { get; set; }

	/// <summary>
	/// Gets or sets the first name.
	/// </summary>
	/// <value>
	/// The first name.
	/// </value>
	public string FirstName { get; set; }

	/// <summary>
	/// Gets or sets the last name.
	/// </summary>
	/// <value>
	/// The last name.
	/// </value>
	public string LastName { get; set; }

	/// <summary>
	/// Gets or sets the full name.
	/// </summary>
	/// <value>
	/// The full name.
	/// </value>
	public string FullName { get; set; }

	/// <summary>
	/// Gets or sets the profile URL.
	/// </summary>
	/// <value>
	/// The profile URL.
	/// </value>
	public string ProfileUrl { get; set; }

	/// <summary>
	/// Gets or sets a value indicating whether this <see cref="SocialNetworkUser"/> is installed.
	/// </summary>
	/// <value>
	///   <c>true</c> if installed; otherwise, <c>false</c>.
	/// </value>
	public bool Installed { get; set; }

	/// <summary>
	/// Gets or sets the gender.
	/// </summary>
	/// <value>
	/// The gender.
	/// </value>
	public string Gender { get; set; }

	/// <summary>
	/// Gets or sets the locale.
	/// </summary>
	/// <value>
	/// The locale.
	/// </value>
	public string Locale { get; set; }

	/// <summary>
	/// Gets or sets the cache date.
	/// </summary>
	/// <value>
	/// The cache date.
	/// </value>
	public double CacheDate { get; set; }

	/// <summary>
	/// Gets or sets the account id.
	/// </summary>
	/// <value>
	/// The account id.
	/// </value>
	public string AccountId { get; set; }

	/// <summary>
	/// Gets the high res profile pic for this user
	/// </summary>
	/// <value>
	/// The pic URL high rez.
	/// </value>
	public string PicUrlHighRez {
		get {
			return "http://graph.facebook.com/" + this.PlatformUserID + "/picture?width=200&height=200";
		}
	}

	/// <summary>
	/// Gets the low res profile pic for this user
	/// </summary>
	/// <value>
	/// The pic URL low rez.
	/// </value>
	public string PicUrlLowRez {
		get {
			return "http://graph.facebook.com/" + this.PlatformUserID + "/picture?width=100&height=100";
		}
	}



	/// <summary>
	/// Creates a new social network user from a given hashtable
	/// </summary>
	/// <param name="data">The data.</param>
	/// <returns></returns>
	public static SocialNetworkUser newFromIOSHashTable(Hashtable data) {
		SocialNetworkUser result = new SocialNetworkUser();
		if (data.ContainsKey("last_name")) {
			result.LastName = (string)data["last_name"];
		}
		if (data.ContainsKey("first_name")) {
			result.FirstName = (string)data["first_name"];
		}
		if (data.ContainsKey("name")) {
			result.FullName = (string)data["name"];
		}
		if (data.ContainsKey("link")) {
			result.ProfileUrl = (string)data["link"];
		}
		if (data.ContainsKey("locale")) {
			result.Locale = (string)data["locale"];
		}
		if (data.ContainsKey("gender")) {
			result.Gender = (string)data["gender"];
		}
		if (data.ContainsKey("id")) {
			result.PlatformUserID = (string)data["id"];
		}
		return result;
	}


	/// <summary>
	/// Generates a string representation of this user
	/// </summary>
	/// <returns></returns>
	public override string ToString() {
		var result = "[SocialNetwork User " + this.PlatformID + ":" + this.PlatformUserID +  "] " + this.FullName + " " + this.PicUrlHighRez;
		return result;
	}

}

Usage.cs

// Use this for initialization
    public override void OnStart() {
		loginButton.GetComponent<tk2dButton>().ButtonPressedEvent += attemptLogin;
		ServiceLocator.facebook.OnLoginFailed += facebook_OnLoginFailed;
		ServiceLocator.facebook.OnLoginSuccess += facebook_OnLoginSuccess;
	}


	protected void attemptLogin(tk2dButton source) {
		ServiceLocator.facebook.login();
	}

	void facebook_OnLoginSuccess() {
		GameLog.fatal("FACEBOOK LOGIN SUCCEEEDED!");

		ServiceLocator.facebook.graphRequest("/me", onMeCompleteRequest);

	}

	protected void onMeCompleteRequest(string path, object result) {
		Hashtable hashResult = result as Hashtable;
		if (hashResult != null) {
			SocialNetworkUser currentUser = SocialNetworkUser.newFromIOSHashTable(hashResult);
			currentUser.PlatformID = GameConstants.FACEBOOK_PLATFORM;
			GameLog.fatal("Current user " + currentUser.ToString());
		}
	}

	void facebook_OnLoginFailed(string result) {
		GameLog.fatal("FACEBOOK LOGIN FAILED " + result);
	}