{fancytooltips} allows to insert tooltips into PDF documents. A tooltip is a popup window that appears if the mouse hovers or clicks particular areas.
The fancytoolstips package allows inclusion of tooltips which contain arbitrary TeX material or a series of TeX materials from an external PDF file. A tooltip is a popup window that appears if the mouse hovers or clicks particular areas. To see the tooltips, you have to open the files in Adobe Reader.