They provide FREE VoIP calls and text messaging via their application. The app is free and the service is free with NO ads. Your friends or family members do need to have the app installed as well for this service to work, but you don’t need to add them to a list. Viber uploads your address book for you and your phone number is your ID. This makes life super easy. Add in 20 million current subscribers, with 12 million active in the last 30 days and cross platform support, you have the makings of greatness. There are also no international charges, which is pretty standard on most VoIP services, but still a very important aspect for many.
Application: Viber: Free Calls & Messages
Developer: Viber Media, Inc