I have been working on a custom WordPress theme with my brother, @erictufts, that has at its very core the need for iOS styled scroll bars.  We had tried every custom scroll bar out there and just could not seem to find a solution that met all of our design criteria.

Our requirements were:

• That the scroll bars use jQuery (since I am really not interested in having yet one more JavaScript library downloaded by the user just to replace the browsers default scroll bars)
• That the scroll bars work consistently across desktop and mobile browsers
• That the scroll bars would fade out as the scrollable pane lost focus
• That the implementation would not require that we add a bunch of extra HTML and CSS to the page
• That the solution be in active development

Nicescroll