I have used Ooma for years. It works great and you can buy the box for about $75. Best Buy has them and I am sure Amazon sells them too. I have a cordless phone base plugged into it and the second phone can obviously go anywhere.
You do have to pay the taxes which are about $4 per month but there is no monthly fee unless you take their optional services. I am not sure how Google would be able to do it without the taxes.
Before the cordless phone I ran a wire out of the Ooma box and plugged it into a wall jack in the bedroom the box is in. That back fed all of the phone outlets in the house and made them live.
Here is a link to Ooma:
https://www.ooma.com/promo/ooma-get-connected