You could use the SimpleViewer Extension for WYSIWYG Web Builder which can be found here.
Instructions on how to upgrade the WYSIWYG Web Builder SimpleViewer Extension to SimpleViewer-Pro are included in the SimpleViewer Extension documentation. This documentation is provided as a PDF file within the extension download. If you have problems upgrading, please contact WYSIWYG Web Builder support.

Alternatively, you could create a SimpleViewer-Pro gallery with one of these gallery creation methods and then embed it in an existing HTML page alongside other content by following the instructions here.