[Plugin: Welcome Gate 2] Installation

I tried to install Welcome Gate 2 Plugin. I didn’t fing any description how to do it so I put html, css and java files to the folder with blog. It works except that squeze page appers every time I visit my blog but it should appear only once per year. How to fix it? In the support they told only that: “You should only see the welcome gate one time and then the cookie gets deposited.”