Mobile VoIP also sometimes written or known as mVoIP (mobile Voice Over Internet Protocol) is a technology that lets you use smartphones and portable tablets (PDA) for making and receiving phones calls (audio). In addition to that you can also use for Instant Messaging / SMS (DATA) and Video calls. All that works via SIP (Session Initiation Protocol) using Internet networks such as:
As VoIP continues to grow and revolutionize the way we use communication, this latest solution comes with numerous features and benefits of the freedom, flexibility and FREE charge.
I list some of the popular mobile VoIP providers that offer free SIP based applications for smartphone software such as android, windows and iOS. Which will allow you to make free VoIP calls as long as you have a Wifi or cellular data.
Visit mobile VoIP providers page for some list of famous companies.