Prevent over-scroll, scroll freeze, scroll "bounce", or whatever you call it, on Safari Mobile.

scrollCap.js

var scrollCap = function ($element) {
  $element.on('touchstart.scroll-cap', function(event){
    var $element = $(this);
    var scrollTop = $element.scrollTop();
    var contentHeight = $element.get(0).scrollHeight;
    var minScrollTop = 1;
    var maxScrollTop = contentHeight - $element.height() - 1;

    if(scrollTop < minScrollTop){
      $element.scrollTop(minScrollTop);
    } else if (scrollTop > maxScrollTop) {
      $element.scrollTop(maxScrollTop);
    }
  });
};