I've got a Windows Phone and I have unlimited calling in the U.S., but I also want to call internationally.

However, I believe "Ringo" may be the only app that will work on a Windows phone:
https://www.microsoft.com/en-us/p/ringo-low-cost-international-calling/9wzdncrdms4n?rtc=1

Anyone ever used Ringo or any other international calling app? How do these apps work, specifically how do you pay for the calls?

 

I've got a Windows Phone and I have unlimited calling in the U.S., but I also want to call internationally.

However, I believe "Ringo" may be the only app that will work on a Windows phone:
https://www.microsoft.com/en-us/p/ringo-low-cost-international-calling/9wzdncrdms4n?rtc=1

Anyone ever used Ringo or any other international calling app? How do these apps work, specifically how do you pay for the calls?

I'd start with my carrier first. I have T-Mobile and I'm pretty sure Mexico and Canada are already free. Other countries are available and prices vary quite a lot. Then I'd go to Skype or FaceTime (OK, not available on a Windows phone) if the people I wanted to communicate with were able to use those.