When I tried to download Facebook Chat Messenger (the official one and not from a third party) from my Windows Phone (through the App store) I couldn't find any official app, only many unofficial FB chat messengers. I want the official one so I checked at https://www.facebook.com/mobile/messenger but I saw apps only for Android and iPhone and not for Windows. Is the Facebook Chat Messenger not available for Windows phones?
Facebook Messenger for Windows Phone is available from 05 March 2014.
Facebook messenger is not available yet for Windows Phone, but it's coming soon: http://www.wpcentral.com/facebook-messenger-announced-windows-phone