This is a quick reference to several wireframe examples
Wireframe Grids are extremely flexible and powerful. You can add HTML text, links and style the cell contents. If you need to merge columns or row cells then look into using the Table HTML tag inside the paragraph widget
MockupTiger wireframes have connectors that can be used to build flowdiagrams
MockupTiger is the only tool that has so many d3js charts for prototyping. Edit the data in the chart and immediately see the chart change. Much better than static image files that are seen in other tools.
Product Management Engineering Dashboard mockup/prototype