I wanted to report that your version 2.1.0 of the user tracking plugin does not install correctly. Upon install only the legacy.xml is installed. I had to manually copy the file remotetrack.xml to the plugin folder in order to get the plugin to work.
I tried to install the extension on three different Joomla! sites that sit on three different webhosts and downloaded the extension multiple times from different computers just in case so this is not an isolated incident or related to something I did wrong.
It seems to me that any testing at all could have prevented me having to pay to be your beta tester. This is not the first time this has happened either. When I first signed up for the "Pro" version there were issues that easily could have been prevented with any testing at all.
You are doing a really good job with this extension so please take a little time and actually try to install your releases so your paying clients don't have to do the test for you.
Thanks for reporting it.
I tested it with several Joomla versions, but sadly Joomla has a very "funny" way to read xml manifest files.
However, I'll publish a new release with two different versions: one for J1.5 and another for J2.5+, so the problem won't show up again.