Google's Voice calling application has won approval to be on the iPhone after more than a year of haggling with Apple. The announcement resolves a stand-off that triggered a Federal Communications Commission inquiry into whether Apple and AT&T Inc., the iPhone's exclusive U.S. service provider, were trying to stifle competition by keeping the app off the popular device.

Earlier this year Google launched a Google Voice HTML5 web app for iPhone users. Today Google is taking the Google Voice experience on the iPhone to a whole new level with the launch of the official Google Voice for iPhone app.

With this native app, users will continue to have access to all the Google Voice features on their iPhone like cheap rates for international calls, free text messaging to U.S. numbers and voicemail transcription. In addition, the user's Google Voice number will be displayed as caller ID when making calls.

The app also features push notifications, which instantly alert users when they receive a new voicemail or text message. Most of the users' calls will be also placed via Direct Access Numbers, making them connect just as quickly as regular phone calls, Google said.

Google Voice for iPhone is available to download from the Apple App Store today. An iPhone with iOS 3.1 or later and a valid Google Voice account are required to use the app. At this time, Google Voice is available in the U.S. only.