Ringo launched in 2014 and was available for use in many countries, though not all supported all three calling methods:- callout, callback and WiFi.
[9] Users could purchase top-up credits through the app for Android and Windows Phone and through the website for iOS to make calls.
The system then switched the call to connect through submarine cables.
[11] At the receiver's destination country the call was connected to a local network again.
Although the call was assigned different local numbers every time it was made, the receiver saw the caller's contact details only.