fMobi is the best Facebook client for Nokia N9.
Chat or share status. Checkin. Upload photos. Comment and like your friends' posts. Look at your friends photos & albums and much much more!
More than 25 languages included!
5/5 I love this app. It's made me enjoy using Facebook through a mobile phone again.
Problems? Check FAQ.
Free version is also available, FMobi 7 day trial version.