Can I add titles and captions to my photobook?

Yes. Tap on the Project title on the top of the book editor, or go to the Cover Edit screen and tap on the title area. Most templates also allow you to add a subtitle. You can also choose fonts for both of them. Any choice will affect BOTH the Title and Subtitle. Text captions are optional on every page. Just tap the T icon to bring up the text box. Then tap on it to enter page captions.