Apple has approved GV Connect, a native Google Voice App. It's available for $2.99. The App seems to be having some issues with people outside of the US getting hung up at the loading screen and on the logging in screen.
Here are the features:
GV Connect is a native iPhone/iPod Touch application which allows you to interact with your existing "Google Voice" account much faster than using the web interface:
‚Ä¢ Place calls using your Google Voice number rather than your mobile number – enter number directly, select a contact from your device's contacts, or call back any number in your history.
‚Ä¢ Send and receive text messages (SMS) from your Google Voice number.
‚Ä¢ Listen to voicemails and recorded conversations right on your device (allowing you to pause, rewind, or fast forward to any point within the message) – voicemails will also show the transcription of the message when available.
‚Ä¢ Mark messages as starred, attach notes to conversations, block/unblock senders, or delete conversations.
‚Ä¢ Easily search in your history by contact, message, or note.
‚Ä¢ Messages are stored on your device for offline access.
‚Ä¢ Composing notes and text messages can be done in landscape mode.
‚Ä¢ Quickly change various Google Voice account settings (call forwarding, do-not-disturb, message notifications, ‚Ä¶) directly from within the application.
‚Ä¢ Automatic checking for new messages while the application is active.
‚Ä¢ Direct access to your device's contacts without needing to synchronize them with Google
‚Ä¢ All communication is done with the Google Voice website directly, no need to hand over your account information to a third-party.
‚Ä¢ Full support for fast app switching in iOS4 and high-resolution graphics for retina displays.
Please note that GV Connect is NOT a SIP/VOIP application and will thus not allow making calls from an iPad or iPod Touch without a separate VOIP/SIP application. GV Connect currently does not support answering a call back to your 'Google Talk' callback number directly on the device.
GV Connect stores your account password securely in your device's keychain for faster login when launching the application – communication is done via secure connections (SSL) to the Google Voice servers and no contact information (other than the contact's phone number which is required to place a call or send a message) is sent to Google. All operations are fully synchronized with your Google Voice account.
Apps that bring Google Voice to the iOS devices have had quite the history with Apple. Such as being pulled from the App Store after already having been available. There are other such Apps on the way as well, such as GV Mobile +.
Some also seem to look at it hoping that it's a VOIP type App, know that it's not.
$2.99 at the App Store