Calling backend with JS, CORS with post method

I am developing application in angularjs, this application will be available to download for anyone.

The problem I have is that in this application I am calling the backend and getting the cross domain origin problem. I already tried it with jsonp but jsonp is not working with POST method.

I want to be able to call backend from any domain/client, don't know how to solve this problem.

Hope you guys can help me somehow.