As nice scroll is a jquery plugin for WordPress site. This plugin will create a nice scrollbar for your site.

Add nicescroll to your wordpress site, it's a jquery (since 1.5) plugin for nice scrollbars with a very similar ios/mobile style. Compatible with the most desktop and mobile browsers. (IE6-10, Firefox, Chrome, Safari, Opera, WP7, Blackberry)

Wp Custom scrollbar is nicescroll wordpress plugin.