Google’s officially Google Voice app has just gone live on the App Store and is available as a free download. Previously, the only options for Google Voice users were unofficial clients such as GV Connect and GV Mobile+.

The app features everything you would expect including Google Voice calling and texting voicemail support and transcriptions, and push notifications. The app is apparently only available in the US as of yet, and requires iOS 3.1 as well as a Google Voice account.

Full list of features from Google below:

• Cheap rates for international calls
• Free text messaging to U.S. numbers
• Voicemail transcription
• Display your Google Voice number as caller ID when making calls
• With push notifications, the app will alert you instantly when you receive a new voicemail or text message
• Most of your calls will be placed via Direct Access Numbers, making them connect just as quickly as regular phone calls

You can download Google Voice for iPhone here.

[iTunes via Google Voice Blog]