Apple’s (AAPL) iPhone 5 quickly became the fastest-selling smartphone of all time when it launched on major U.S. carriers and in key international markets one week ago. The Cupertino, California-based company sold 5 million new iPhones in the device’s first three days of availability alone, leading some to call the launch “epic” despite having missed a number of Wall Street analysts’ lofty projections. Sales have seemingly remained strong since then and on Friday, the iPhone 5 becomes available on regional U.S. carriers including Appalachian Wireless, Cellcom, Cricket, C Spire, GCI and nTelos. Apple’s new iPhone also launches in 22 additional countries around the world on Friday including Austria, Italy, Netherlands, New Zealand, Portugal, Spain and Sweden. BGR reviewed the iPhone 5 earlier this week and called it Apple’s most impressive mobile feat to date.