Download of PrestoPhoto 6.4 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free Mac app was originally developed by Viovio, Inc. The software is included in Design & Photo Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
PrestoPhoto helps you print your Apple photo books. The tool allows you to create and manage multiple photo book projects within Photos. Integrating familiar templates and unparalleled freedom of design, you can make photo books exactly how you want to.
You may want to check out more Mac applications, such as Ashampoo Cover Studio 2 for Mac, ImageBuddy or Panoweaver, which might be related to PrestoPhoto.