Check out app warp - it pretty much has all the server code written for you already:
It's mostly used for games, but you can easily use their services for IM.
Question
Basically I'm trying to develop an App that sends some information (Text and Images) to a server and then this server redirects the info to a other devices.
What framework do you know to handle realtime communicaction between users?, I've checked Firebase (Firebase Cloud Messaging), and also I have checked frameworks like ionic to be able to develop once and then deploy in various platforms.
No correct solution
OTHER TIPS
Check out app warp - it pretty much has all the server code written for you already:
It's mostly used for games, but you can easily use their services for IM.