No other job is as rewarding and demanding as building an iPhone app is. It is not really in the hands of the developer for the success of an iPhone app. Many factors operate jointly for every iOS application's success in the market.
Learn how to create flexible layouts using relative units in CSS. New relative units added in CSS3 include vw(viewports width), vh(viewports height), vmin(minimum of viewports height and width), and vmax (maximum of viewports height and width).