So like everyone else I spotted this referrer on my stats and came to this page in search of answers.
So this is the way I see it
The site knows that it is webmasters and developers viewing the stats
The buttons are very nice, easy to attach to any site and are tempting to use. . . but
Whilst they are not going to do damage today and they work as expected the issue is we know nothing of the owner of the site or of the domain, we don’t know the intentions are of the owner. The domain does not show the registrant details. The site has no terms of use, no contact details.
We also know the domain is for sale
So my advice is not to use the service because once the script gets a decent amount of installs on web sites the script can be changed to; lets say throw a pop up to a visitor, add invisible back links to sites or even redirect users to other sites.
So Users Beware