PHONE for Google Voice & Gtalk offers a feature-rich toolset that mimics the phone settings on your iPhone in a standalone app. The result is a good replacement for your cellular number or a good tool to take your Google Voice number with you on your iPhone. Better than Google's first-party Voice app, PHONE offers a range of tools and quick, streamlined performance in a familiar-looking interface.
When you first access PHONE for Google Voice & Gtalk, you'll need to sign in to your Google account. From there, however, the rest of the setup is a breeze as it walks you through connecting with contacts, setting up the dial out features, and more. Once done, the app will work exactly as your phone app would work through a cellular carrier, complete with missed call logs, text messaging, and contact management -- all from a single interface. The dial out feature is fast and the interface looks and feels like it belongs on the iPhone. Our tests were all very positive with performance mirroring that of real phone calls without as long of a wait as you'd get dialing through your Google Voice number, normally.
If you have a Google Voice number or are considering adding one for business calls or long distance, then this is a great app to download. It's free, too; and while there is an ad on the screen most of the time, it rarely gets in the way or slows anything down. All around this is a very well-crafted app.