It’s free and easy to create page-flipping picture book dummies using Ourboox.com.
All you do is sign up for Ourboox, click the Create button, give a tentative title and you’re on your way.
On any page you can add live text or an illustration (as jpeg or png). You can edit at any time, add pages, etc.
There is a “Make Private” button which allows you to keep your dummy book out of the public domain. You can still share it with others via its private alphanumeric url.
Here is the private link of this book: https://www.ourboox.com/book-preview/745596/
You can also embed materials such as videos, maps and puzzles. But that, as they say, is another story.