According to the official website, it's not necessary to just buy the application. Based on its description an features, if you want results, certain aspects and functionality have to be bought from the same page or the page listed in the FAQs. The thing you have to buy is called traffic and SEO promotion.
However, if you insist on using it, then get in touch with the developer and ask for instructions.
You can use the following contact form: http://websitebooster.net/contact.html
