Fake Call and Sms - Fake Call and Sms app is a fake message sender and caller app that provides features through which you can receive as well as can send simulated messages to desired contacts.
Openfire - Openfire (formerly Wildfire) is a cross-platform instant messaging (IM) and groupchat server.
WhatsFake - Make fake conversations that look just like WhatsApp
Prosody - Prosody is a modern flexible communications server for Jabber/XMPP written in Lua.
SMS Class Tools - SMS Class Tools is a fake message generator that allows you to have some fun with your colleagues and friends.
Matrix.org - Matrix is an open standard for decentralized persistent communication over IP.