Click "read only", then paste this into your browser bar and hit enter...

  javascript:(function(){modals = {'showModal' : function(){}};})();

...to be able to try it out without signing into Google or Facebook. Doesn't do anything fancy, just overrides the function responsible for the "Sign up" pop up, and replaces it with an empty function.

Hope this doesn't piss anyone off, just trying to be helpful. Seems like a nice product that people will enjoy thoroughly.