For storing users data on cloud you can use our App42Cloud API's. Message/Queue Or buddy services provides a way to post a message on cloud and then receive that message on other end but they did not provides listener and is pull based. So using these service for messaging you might end up with making lots of API call and it is not suitable for multiplayer kind of application.
AppWarp solution is suited for this kind of application and can be implemented on cross platform for multiplayer messaging. You can use both together for storage and messaging purpose hand in hand.