iCallPro is the Mobile Dialer that allows to make VoIP calls from any of the android devices and it uses 3G/Edge/Wi-Fi Internet connectivity. It is developed based on the requirements of VoIP Providers business needs. ICallPro Features: It uses SIP protocol based for signaling. Supports G729, PCMU, and PCMA codecs. Runs behind NAT or Private IP. User Friendly Interface.