BeeBEEP - You can message and share files inside your intranet without a server.
LAN Messenger - LAN Messenger is a decentralized UDP IM-style chat client which supports usernames...
Send Anywhere - Send whatever you want, wherever you want
BORGChat - BORGChat is a LAN messaging software program.
SHAREit - SHAREit allows you to transfer files and data from your phone to another device without having to rely on WiFi or a data plan.
Output Messenger - Secure instant messenger app for office provides seamless instant messaging solutions for all office, corporate and enterprise business communication needs.