HD Dialer Pro!

HD Dialer Pro offers a simple user interface and superb audio quality for smooth Voice over IP experience. Key features include:- Bluetooth support.- Lowest battery usage with highest reliability / stability on all iPhone models.- Lowest audio latency of all iPhone models.- Excellent audio quality, even on older devices.- Supports calling over WIFI/EDGE/3G/LTE.- SIP stack fully compliant to RFC.- Background / multitasking support.- Speakerphone mute and hold.- Supports sending of DTMF.- DNS SRV.- Built-in echo cancellation.- STUN support.