Chat clients limited to one-on-one conversation are going the way of the dodo. We've got numerous options for group messaging including: Facebook Messenger, WhatsApp, Google+ Messenger, Live Messenger, and we're even pretty sure Babel (or whatever it will be called) will join the list. Today, popular cross-platform chat app, Tango, steps up to match its competitors.
The additions to the interface are very straightforward. You can pick multiple people from your contact list to start a conversation and at any time add new people or leave the chat altogether from the participants screen.