Smartcall

Smartcall.pw is a mobile application for Android and other smartphones,
offering VoIP Calls from data enabled mobile phones (2G/3G/4G or WiFi) to any landline or mobile devices around the world.
Features:
*VoIP Calls via Wi-Fi, 2G / 3G / 4G.
*Works in all Countries and all Networks across firewalls.
*Smooth voice quality
*Echo cancellation
*Uses very less bandwidth.