This addon is based https://apps.oscommerce.com/iWJbv&modal-info-popup-layer-for-bootstrap-o
credit to original author.
If you want your customers to take note of certain informations, there is one way to make them aware by using a pop-up window or a layer. This contrib uses a jquery popup layer for this purpose. When a customer enters the shop the first time, a info popup layer is once laid over the page - regardless on which site the customer enters the shop. The individual messages can be created via a pop-up manager as plain text, html-text or graphics in the admin area.There you can also specify a start and an expiration date for the display of messages.