A better setTimeout

main.js

$(function(){

  $('#boxes li').on('click', function(){
    var self = $(this);
    self.addClass('selected');
    wait(self, function(){
      this.removeClass('selected');
    }, 1000);
  });
  
  function wait(context, callback, time){
    setTimeout(function(){ callback.call(context); }, time);
  };
  
});

I like how you solved this!