I installed the plugin, and was immediately locked out of my site: "Restricted access". Upon further review, I found that this is not a unique issue. Upon checking the author's site (JoomlaStats), I see the answer given by RoBo (admin) is:
"If you have access to the database (using phpmyadmin for example) then you should be able to deactivate the just installed component/module. Please check Joomla site/forum for more info."
Gee, that was a lot of help.

Initially, I was a little frustrated at not being able to find the REGISTER link in order to download the plugin (top middle "Why Register?"). Once I got registered and downloaded the plugin, I spent an hour or so playing around with it.
Now, I'm fairly new to Joomla. I've been playing around with it occasionally for a few months, so there is a little bit of a learning curve for me. I was a little disappointed that there were not more configuration options in the pluginadmin panel. In order to enable the buttons I wanted, I had to edit the SITE/plugins/content/ultimate_bookmarking_plugins_buttons.xml file. Ultimately I found that one of the the last options (AddThis.com - JavaScript Drop Down Badge) contains a dropdown giving access to all the included sites. I made this available top and bottom, and found it to be a very clean and professional looking addition to my test site. I will definitely add this to my live site when I migrate from WP to Joomla (