Does this differ from launcheffectapp.com which provides the viral referral free?
If all you want is a theme for Wordpress, this is a great one: http://maxfoundry.com/themes/liftoff/
KickoffLabs is a complete platform for launching a viral landing page and requires no hosting/setup for end users.
The API we release today is an attempt to add more flexibility and options for our customers.
Thanks, Scott