Defying Apple's effort to keep control over iPhone telephony, Google on Tuesday delivered Google Voice to iPhone users in the form of a Web app.
Google made Google Voice, its invitation-only voicemail and discount calling service, available through mobile applications for the BlackBerry and Android devices in July.
But Apple refused to approve an iPhone version of the Google Voice mobile app. When the Federal Communications Commission began looking into the situation, Apple said that it did not approve Google's application because "it appears to alter the iPhone's distinctive user experience by replacing the iPhone's core mobile telephone functionality and Apple user interface with its own user interface for telephone calls, text messaging and voicemail."
Google said it would explore alternatives to make its service available to iPhone users and now it has found a way around Apple's oversight through the iPhone's Safari Web browser.
Those with Google Voice accounts can access the Google Voice Web app at the following URL: http://m.google.com/voice. After opening that URL in the iPhone's Web browser, the "+" command, followed by the "Add to Home Screen" command, can be used to create a Home Screen icon that will launch Google Voice, almost as if it were a native iPhone app.
The Google Voice Web app allows Google Voice users to display their Google Voice phone number on outbound calls, to review their Google Voice inbox and transcribed voicemail messages, to send and receive SMS text messages using their data connection, and to place calls using Google's low-priced international calling rates.
In a blog post, Google engineer Michael van Ouwerkerk said that the new Google Voice mobile Web app works on iPhone 3.0 devices and on Palm Web OS devices by using HTML5 technology.
HTML5 is the latest version of the Hypertext Markup Language used by Web browsers to render Web pages. Because it's an open standard, Web applications can be written by anyone, without the approval process Apple requires for native iPhone applications. Though the HTML5 specification isn't yet complete or universally agreed upon, companies like Google and Mozilla have been adding support for HTML5 technologies in an effort to encourage standardization and to support non-proprietary development.
Among developers who chafe at having to conform to Apple's rules and those who want to reach the entire mobile market rather than creating and maintaining multiple device-specific builds of their apps, there's hope that HTML5 will make Web applications competitive with native mobile apps.
That hope may be tested on Wednesday, when Apple is expected to introduce a new tablet computer, a move likely to underscore the value of Apple's iTunes ecosystem for content distribution and purchasing.
But the availability of Google Voice for iPhone users, despite Apple's wishes, shows that the Web can reach deep into the most well-defended walled gardens.
Google's development mantra last year was "the Web has won." It was something of a premature declaration of victory, but now at least Google's claim seems plausible.
Raven Zachary, president of iPhone development consultancy Small Society, said in an e-mail that while he has focused primarily on building native iPhone apps, Web apps nonetheless have a place.
"Some companies have even built hybrid apps -- essentially a native iPhone app wrapper to a Web site that can then be distributed on the App Store," he said. "While this is not the best user experience, we are seeing more and more of these hybrid apps appear on the App Store."
Zachary continues to believe that native applications will always offer the best user experience and application performance. But he notes that some companies develop both native and Web apps.
"A company like CNN has both a mobile optimized Web site for iPhone and a native iPhone app," he said. "You don't have to make the choice between one approach or the other. It really depends on your goals, your user base, and your budget."