Some web developers have reported some problems related to iOS 4.3 and the way Safari works with certain web apps. Web apps are applications specially made by the owners of certain sites that allow mobile phone users to interact much more easily with the site. Gmail has something like that, YouTube has something like that, many other sites have it and a lot of people use this kind of web applications. Unfortunately for iDevice owners, Apple appears to be implement some changes in iOS 4.3 that reduce the performance of web applications. More precisely, web applications added to the homescreen are twice as difficult to open as normal web applications opened in Safari.
If a web app is run from the iOS 4.3 home screen – in other words, if it is saved to the screen alongside local apps downloaded from the Apple App Store – it runs roughly two to two and a half times slower than it does in the browser, according to various tests. It appears that whereas Apple has updated the iOS 4.3 Safari browser with its high-speed Nitro JavaScript engine, Nitro is not used when web apps are launched from the home screen.
"Essentially, there are two different JavaScript engines," says Alex Kessinger, a mobile application developer and blogger who has focused on building web-standards-based apps for the iPhone. "They're not using the new JavaScript engine with applications that launch from the home screen."
In the images above we have an example with the Sunspider benchmark run in Safari on the left and opened as a web app from the homescreen on the right. The one opened in Safari was tried in 4000 ms, while on the right side the one opened from the homescreen needed 10000 ms to load. So if you add a web application to the homescreen, there is a chance that it will open with up to 2.5 times more difficulty than if you accessed it from Safari. Some say that Apple would try to "force" web developers to introduce applications in the AppStore, where Apple takes a part of the profit registered by developers from sales. No matter what Apple tries to do, it's quite clear that web applications run from the homescreen on iOS 4.3 will be more difficult to open.
