module.js

var app;

app = (function(){
  
  var myPrivateVariable = "my private content";
  
  var application = {
    init: function(){
      console.log(myPrivateVariable);
    },
    cache: function() {
      // impl
    },
    bind: function() {
      // impl
    },
    blabla: function(){
      // ....
    }
  }
  
  return application;
  
})();

app.init(); // > my private content
app.myPrivateVariable // > undefined