Within Teamwork Chat, you can create a new channel at any time in the Android mobile app.
In the Channels tab of your Chat app, select the blue + icon near the bottom right of the screen to open the Create Channel modal.
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In the Create Channel modal, you can add a title and description for the channel, as well as add users.
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At the bottom of the modal, you can set the channel visibility to private or public. When a channel is private, only people added to it will be able to see it and search for it.
For more information, see: Downloading the Teamwork Chat Mobile App