Following the relaxation of its application development and submission guidelines as well as months of government inquiries after being pulled in the Summer of 2009, Apple has approved two native third-party Google Voice applications in GV Connect and GV Mobile+, which allow Google Voice users to make voice calls and send SMS/MMS messages via Google Voice as well as take advantage of service specific functionality, such as advanced call screening and call recording. GV Connect is available now from the iTunes Store for $2.99, while GV Mobile+ has yet to appear on the store, with final approval coming in the last 48 hours.
Update: GV Mobile+ is now available on the App Store for $2.99.