This is as easy as it gets! 

You can access different chat boxes directly through the dashboard or, whenever a customer wants to place an order and enquires about an item, you will get a push notification that will lead you to the chatbox with that customer. 

After opening the chatbox, you can see all the messages that the customer has sent or you have sent. On top of that, you have the option to attach items or media, and, wait for it, create custom items as well!