Thank you for pointing me to this! To date I had not seen anything similar.
Perhaps the biggest differentiator is that PhoneCard works in the opposite direction, too. For example, you can purchase a phone number in the UK and have it forward to a US number. Also, PhoneCard calls you, while Ringo appears to make an outgoing call. In much of the world besides the US/Canada, incoming calls are free (even on a mobile/cell phone), so this means you pay for the call once instead of twice.
Perhaps the biggest differentiator is that PhoneCard works in the opposite direction, too. For example, you can purchase a phone number in the UK and have it forward to a US number. Also, PhoneCard calls you, while Ringo appears to make an outgoing call. In much of the world besides the US/Canada, incoming calls are free (even on a mobile/cell phone), so this means you pay for the call once instead of twice.