All, I have a requirement that I need to develop an facebook messenger client application using Xcode for MAC. At startup, the UI must comprise of login page where the user has to provide facebook credentials to login. Upon logging in, using the client/app, the user must be able to write on his wall and chat with other online friends. I found a similar app developed for Windows at this link. Could you guys guide me as to how I go about approach this problem. Thanks & Regards.