Users of the iOS version of Google Hangouts can now place outgoing voice calls -- free to numbers in the US and Canada -- and can, if they're in the states and also have a Google Voice number, receive calls in the app as well.
Though Google isn't charging for calls to the states or to the Great White North, people phoning elsewhere will have to buy a calling credit from the company to do so. Google says its rates can be significantly lower than those of competitors.
On a how-to page for calling from the iOS Hangouts app, Google also notes that "calls from your Hangouts app won't use your cell phone carrier's voice minutes, but it will use your data plan. Contact your cell phone provider for more details on charges and usage."
For Google Voice users, there's a how-to page for receiving calls as well.
- See which of your friends is using Hangouts, and who can be reached right now
- Send and receive animated GIFs that play inline
- Hangouts will temporarily turn down your music (instead of stopping it) when you receive an incoming message