Ring4 uses the internet (like Whatsapp, or Skype), and works over Wifi or a Data plan. The quality of the calls depends on the stability of the internet connection.
In order to make or receive calls Ring4 uses the internet and works over Wifi or Cellular Data.
The quality of the calls does depend on the stability of your internet connection.
However, this gives you the flexibility to use a wireless hot-spot or a data stick and allows you to use roaming free when you travel internationally.
You now have true flexibility with your options for calling and texting between your cell phone and Ring4!