For enthusiasts, there are community-driven projects that aim to bring modern web services to legacy Symbian devices:
: These apps are no longer available on official stores. You would need to search reputable archive sites like Dailymobile or All About Symbian for a .jar file. facebook app for nokia e90
Several developers extracted the chat protocol from the old Facebook app and built tiny chat clients. These connect directly to Facebook’s XMPP gateway (which was shut down by Facebook in 2015). These no longer work. facebook app for nokia e90
there is no longer a modern, officially supported Facebook app for the Nokia E90 Communicator facebook app for nokia e90