Zepto.js smooth vertical scrolling method. Implementing this code turns all anchor links with the class "scrollTo" into smooth scrolling anchor links. Rework of the foundation.js library method.

zepto.smoothScroll.js

function smoothScroll(el, to, duration) {
    if (duration < 0) {
        return;
    }
    var difference = to - $(window).scrollTop();
    var perTick = difference / duration * 10;
    $(this).scrollToTimerCache = setTimeout(function() {
        if (!isNaN(parseInt(perTick, 10))) {
            window.scrollTo(0, $(window).scrollTop() + perTick);
            smoothScroll(el, to, duration - 10);
        }
    }.bind(this), 10);
}
$('.scrollTo').on('click', function(e) {
    e.preventDefault();
    smoothScroll($(window), $($(e.currentTarget).attr('href')).offset().top, 200);
});