I looked at it earlier today and it eluded to importing my cell number and such. I use a prepaid simple cell phone and it ain't cheap. I want to keep my number but get away from having to buy expensive minutes. So I am unsure, if this is for me or not.
Computer, I have used Skype in the past and sometimes it works, sometimes not. Probably attributed to user error.
I looked into it a bit and you can do what you are asking. It is not hangouts that you make the call with. Hangouts is an integration of several Google services in one program (Google Talk, Google Voice, Google Chat and Google+ messanger). What you are looking for is Google Voice, which, as mentioned earlier, must be downloaded and setup with a US IP. You can use Hangouts for video chats and text messages with anyone that has Hangouts installed on their computer or cell phone. If you are looking for a VOIP it might be worth looking into MagicJack and Vonage. I have both the MagicApp and Vonage on my phone but I don't recall ever having used them. Hangouts and Viber works perfectly for my needs. Five Best Mobile VoIP Apps
I have a magicjack and it has served me well(see earlier post) I was looking more for video/voice/chat similar to YM. I've used YM extensively with aking Asawa, long before we even married. Can't get any cheaper than free.
For video chat Hangouts works much better than Skype. I haven't used YM for over a decade so I can't compare. I stopped using YM because of the ridiculous amounts of spam I used to get on it, though it was the best messanger at the time for meeting filipinas. As I mentioned earlier, I call from Afghanistan internet to the Philippines and have little issue. Quite amazing considering the bandwidth available in both countries.