Then there are the "lingering death" products, such as Google Voice. Google bought that from Grand Central in 2009, and it's still basically Grand Central. There's a running joke about Google Voice acquiring an API that's been in a bug report for five years now.

I think there's a phone interface feature associated with Google Hangouts. ("Google Hangups?") But it probably requires that everyone you talk to have a Google account. All these little closed-world communications systems are a pain.