After 16 short months in the Apple App Store approval process, Google Voice is now available as a native app on the iPhone.

The Google Mobile blog announced today that Google Voice would be available to Apple’s iPhone users.  The app caused controversy almost two years ago when it was put into ‘App Store Purgatory’ by Apple and became one of the focal points of a government investigation into Google GOOG , Apple AAPL and AT&T T .

A year and a half later, it is in the App Store, ready for iPhone users to download.

Interestingly, the Google’s post was written a week ago but only made public today.  The delay is probably to account for the time it took for Apple to finally sign off on the product after its most recent submission.

I am a huge fan of Google Voice, which allows you to route calls to any of your phones, transcribe voicemails and make inexpensive long distance calls.

Google points out:

With this native app, you’ll continue to have access to all the major Google Voice features on your iPhone, like:
  • 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
In addition to these benefits, the app provides some features that make using Google Voice on your iPhone a much better experience:
  • 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

Recently, Google enabled Google Voice VoIP on Gmail, which allows you to make calls in a Web browser right from the Gmail page.  Google Voice is also being rolled out to enterprise users.

Google Voice on the iPhone is only available in the US and can be downloaded for free here.