From your Discover screen, you are able to view your assigned users within your network.
To communicate with a user, click on their profile picture from the Discover screen and select "Send Message".
You must have your availability indicator turned on in order to send a message.
If you have already begun a conversation with the user, you will be opted back into the same conversation.
Another way of communicating with a user is by going to the "Messages" screen.
Find the conversation thread with the user, click on it, and you are able to jump right back into the conversation.
You will receive push notifications when a new message is received. Just be sure that you allow push notifications when the pop-up appears during the account setup process for both mobile devices and when using the online version of the app.