When you build website wireframes or prototypes, clickable mockups is a standard requirement.
MockupTiger when released had Clickable prototyping feature using the Text widgets
Now all the text widgets, icons can be linked. There is a new element called hotspot that you can overlay on any kind of object/widget to simulate Clicking or interactivity
Read more about building Clickable Prototypes using Mockups
MockupTiger Wireframes is the best HTML5 wireframing application for Websites and Business Intelligence dashboards