Why did Apple okay RingCentral?

Here's a question the Federal Communications Commission neglected to ask Apple in its inquiry into why the company rejected — or as Apple prefers, declined to approve — Google Voice: Why has a free app that does essentially the same thing — and would seem to raise the same red flags for Apple — been sitting on the App Store for nearly 10 months? The app is called RingCentral Mobile and not only does it perform most of the same functions as the Google app that's making all the headlines — universal telephone number, voicemail, dial-by-name directory, click-to-call, call forwarding, answering rules, call screening, music on hold, etc. — it was the template on which both Google Voice, and its predecessor, GrandCentral, were built.