Web Apps And Optimized Sites : Whereas a “proper” iPhone app is downloaded to your phone and runs as a standalone piece of software, a “web app” is an application that takes the form of an interactive webpage.The term is also often used to describe plain old webpages specially designed to fit on the iPhone screen without the need for zooming in and out. As such, you might also hear people refer to them simply as iPhone-optimized webpages and websites.
Unlike many “proper” apps, web apps will usually work only when you’re online. On the plus side, they tend to be free – and they usually take up no space in your iPhone’s memory. There are exceptions to these rules, however. For example, Google’s Gmail web app uses a “database” or “super cookie” to store some information locally – which does take up space and enables some functions to be carried out even when the iPhone is offline.
Several websites – including Apple’s own – offer directories of iPhone-optimized websites and web apps, arranged into categories, though increasingly these sites look out of date, due to the rise of fully fledged iPhone apps.
Apple’s web app directory apple.com/webapps
Whether or not they call them “web apps”, many popular websites offer a version for browsing on mobile devices in general or iPhones specifically.These not only fit nicely on small screens but also load much faster, since they come without the large graphics and other bells and whistles often found on the full version of their websites.
Usually, if the server recognizes that you’re using a mobile web browser, the mobile version of a site will appear automatically. Occasionally, though, you’ll have to navigate to the mobile version manually look for a link on the homepage. Mobile sites often have the same address but with “m” “mobile” or “iPhone” after a slash or in place of the “www”.