Here is my blog/test site http://strilaeff.net It is the main site in a multisite installation and I activated this plugin only for this site (not network activate).
I installed it with the defaults (it created the "search" page), and put the widget in the footer. I have standard categories and tags which you can see work by using the normal menu.
It does nothing in chrome (except show the search bar).
In firefox, it gets the cat and tag terms, but always returns empty results. There is an unexpected link on the search results page to that same page. Other pages (like "About") show the title but it is not a link.
I'm evaluating this because I need the features of the pro version (it can find custom post types using custom taxonomies, right?), but you have to help me get the basic version working out of the box or I'm not interested.