如何在iOS设备上构建视差滚动

Today I saw the most amazing ipad app that I was assured was written using html5, css3 and javascript... the best part of the app was they had perfectly created a parallax scroll... My question is... how?... I can not find any documentation on it being possible to create a parallax scroll on iOS devises... if someone could give me a link or any advise on how to do this that would be most appreciated... anyone?... kind regards J Today I saw the most amazing ipad app that I wa