If you are looking for an easy solution to display movable or static grids on terrains that will contour to the hills and valleys, this is the plugin for you.
Try the Demo!
This works out of the box with one script, and needs no other plugins.
It also works with Vectrosity just as easily.
Simply attach the script to your existing building or other object you want to display a grid under, set a few variables, and you have a grid that maps to your terrain.