I second the other great reviews! – Ringo: Low cost calls Review

Ringo is truly great! I agree completely with other reviewers about the great call quality. I use it to call home regularly from all over the world. But the very best thing about Ringo is that you never again have to arrive in a foreign country, buy a SIM card, figure out how to dial in a foreign language, etc. etc. etc. With Ringo on your phone, you just find free wifi and call whoever you need to. Great for calling your hotel or Air-BnB host to coordinate. And the rates are incredibly cheap. My friend and I talked for an hour when he dialed me up overseas using his US cell plan. He'll never do that again! He paid just over $100. When I called him the next time using Ringo, it cost me only about 20 cents for the call. I also like Voca and use it occasionally if there's ever a problem connecting for some reason. Between the two, you'll be covered wherever you go.
Review by Bife de Chirizo on Ringo: Low cost calls.