Simple Integer Counter JQuery Plugin

intcounter.js

$.fn.countInt = function(duration, from) {
    from = typeof from !== 'undefined' ? from : 0;
    duration = typeof duration !== 'undefined' ? duration : 1000;
    var $this = $(this);
    var to = $this.text();
    $this.text(from);
    $this.start = function() {
        var stime = new Date().getTime();
        function step() {
            var now = new Date().getTime();
            var progress = now - stime;
            var oldValue = $this.text();
            var value = (to - from) * progress / duration;
            if (Math.abs(value - oldValue) >= 1) {
                $this.text(Math.floor(value));
            }
            if (progress <= duration) {
                requestAnimationFrame(step);
            }
            else {
                requestAnimationFrame(function() {
                    $this.text(to);
                });
            }
        }
        requestAnimationFrame(step);
        return $this;
    };
    return $this;
};