These are the specs to create html5 overlays.
1) It must be a self-contained zip with index.html.
2) It must be a responsive page
3) the content should be formatted in pixels, same size of the image you want to cover in the print PDF
4) <meta name="viewport" content="user-scalable=no, width=XXX" />
to be inserted in the tag <head>. The width value is the size in pixel of the image in the print PDF ( see point 3)
index.html will be shown on the device every time the page is sees on screen.
The URL of this file can be added in the original PDF or from our multimedia tool in the dashboard, selecting the annotation type “HTML5overlay”.
PLEASE NOTE: You must .zip the files, not the folder.