If your friend is also using joyn, you will see their availability next to their name in your contacts list. Green means online (or available), red means busy, yellow means away, and grey means unavailable. If they are online, they should be available to chat and share files with you instantly through joyn chat. If not, it means they haven’t updated their availability or you haven’t received their latest availability yet.
To start a group chat, press the filter at the top of your contacts until “groups” is shown. Now press the small arrow next to the group you’d like to chat with. Next select “Group chat” and press “Start.” Or, to start a chat with friends you don’t have assigned to a group, open the first contact and press “Chat.” Now press the "plus" sign and select the contacts you’d like to add to the chat. Now press “Start” to begin the chat. You’ll see everyone’s responses in one convenient thread. And, if your friends are available, it’s all in real time.
If the message bubble is yellow, it means your message was delivered in a real- time chat by joyn. If it’s white, that means the message was delivered as a text message since your contact is either unavailable or not using joyn.