Simple animation for elements as they enter the view port. Update: Just use WOW.js

animate.css

.selector {
	width: 100%;
	height: 300px;
	margin: 40px;
	background: black; 
	/* The defaults */
	opacity: 0;
	margin-top: 90px;
	transition: all 500ms ease;
	-moz-transition: all 500ms ease;
	-webkit-transition: all 500ms ease;
}

.selector.on {
	/* The in view styles */
	opacity: 1;
	margin-top: 20px;
	transition: all 500ms ease;
	-moz-transition: all 500ms ease;
	-webkit-transition: all 500ms ease;
	-moz-transition: all 500ms ease;
}

visible-animate.js

var tiles = $('.selector');

$(window).scroll(function() {

    tiles.each(function(i) {
      var a = $(this).offset().top + $(this).height();
      var b = $(window).scrollTop() + $(window).height();
      if (a < b) $(this).addClass('on');
      if (a > b) $(this).removeClass('on');
    });
});