Need a sign up\sign in on the site, managing referrals and earned "points"
User signs up (mail and password), he receives 100 points, he receives the invite (referal) link (like domain.com/ref=01)
And for each invited friend he gets 1,000 points.
The sql database gotta have user id, user mail, the ip at the moment of registering, who invited him, users that he invited and how many "points" he has.
As a protection against cheating - blacklist some email domains and limit the registration more than 1 time from one ip.
Sign in is just on the main page of the site, does not throw anywhere, everything is on the landing page. After signing in, at the place where form was located - show the ref. link and "share" buttons and two fields: "You have invited - X" and "Your balance - Y points"
And we need admin panel to see the statistics - how many signed up today\ yesterday, who invited biggest amount of users.
I'll listen to the price proposal, I need it as quickly as possible.