“The script development began because mobile webkit (on iPhone, iPad, Android) does not provide a native way to scroll content inside a fixed width/height element. This unfortunate situation prevents any web-app to have a position:absolute header and/or footer and a scrolling central area for contents.
While latest Android revisions are supporting this functionality (although support is not optimal), Apple seems reluctant to add one finger scrolling to divs.
In addition to all previous iScroll features, version 4 introduces:
Pinch / Zoom
Pull up/down to refresh
Improved speed and momentum
Snap to element