It sounds like you're referring to the (a feature phone running Series 40 OS) and a .JAR file that allowed Facebook Chat functionality—likely eBuddy , Nimbuzz , or a dedicated Facebook Chat J2ME app from the late 2000s / early 2010s.
If you need chat on a Nokia 2700 now, the only option is or IRC via J2ME IRC clients (e.g., wirc.jar ). facebook chat jar for nokia 2700
Would you like a step-by-step guide to running these old JARs in an emulator, or a deeper protocol dump of the Facebook XMPP handshake from that era? It sounds like you're referring to the (a