I've been using Google Fi for several years, both in the US and when I travel abroad. Rarely is my bill over $30/mth (I use wi-fi at home and work), and overseas long distance calls are only $.20/minute. Unless you are connected to wi-fi, then they are free. Same with text messages.
Now Google is adding this service to most Android phones and many iPhones.
To get $20 off your first bill click on the following code.
Check it out and redeem your code here: https://g.co/fi/r/6NR87A