Just a followup on how you start building your lists. You can visit profile page of users mentioned on the top right. Or you can visit any of the "Lists" present on the header section. You can search for a movie you wish to recommend too.
Why would you sandbox your app in Facebook anyway? Is there any particular reason for putting it in an iframe on Facebook?
The app is basically a stand alone web app. And Iframe seemed to be the most painless way of integrating it with facebook. It was laziness and not any strategy which led me to decide on Iframe.