Google has updated its Google Voice service in the United States to support iOS 6 and the larger iPhone 5 display, enabling users of the newer handsets to carry on using the Google Voice service.
Google Voice aggragates multiple different phone numbers and turns them into a single Google Voice number, it also enables users to send and recieve text messages for free. Users in the US can also place domestic calls for free, or $0.01 per minute to place calls elsewhere.
The service was launched in 2009 by Google, and has 1.4 million users in the US. The app was initially rejected by Apple as it competed with the core Phone functionality, although Apple later approved the app following a FCC inquiry.