Interaction between same apps on two different android devices?

Question

Android

Actually the question is as follows. There is an application. We put it on two different Android devices. The task is to send data from one application on the first device to exactly the same application on the second device. Also in the future, you will need to send data to several devices at once.
Since there is no much programming experience for Android, I would like to know your opinion on solving such a problem. Or just direct in the right direction, where to think so to speak.
PS And I'm also interested in how to find the devices on which your application is installed.
Thanks everyone for the comments and advice.

Answer 1

Set up a server on the Internet that your applications will access.
Thus, you will know the devices on which the application is installed and will be able to transfer data from one device to another through the server.

Answer 2

You can use C2DM , which I wrote about here .