When viewing or building a book in ZooBurst you may notice floating exclamation points floating over the heads of some characters. These markers indicate that the character in question has been assigned some "chat" text by the author of the book. When viewing a book using the ZooBurst book viewer you can simply click a character (or its exclamation point) to cause the full text bubble to appear on the screen. A small "more" button will appear if there is more text than can be displayed inside the chat bubble - clicking this button will cause the chat bubble to expand to fill the entire screen.
When you are building a book in the ZooBurst book builder you can use the "Character Text" box at the bottom of the screen to view / edit text that is associated with one of your characters. If you click in this box you will be presented with a pop-up window that will allow you to edit the text, including the ability to change the font color, style the text using a bold or italicized font and even add in hyperlinks to other websites.