I paid with Paypal, I downloaded the .zip, extracted the file I was interested in, uploaded, set up... and now it is working on my website!
Altogether, 15 minutes.
I have just a small problem of layout, but I am going to insert a request int he forum.
I have to say that it worth the money I spent. A easy to use plugin, doing exactly what I was looking for.
Please, keep on the good job!