HappyTalk

HappyTalk lite 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 google play.

- Lowest latency of all android softphones.

- Excellent audio quality, even on older devices.

- Supports calling over WIFI/EDGE/3G/LTE

- SIP stack fully compliant to RFC.

- Background / multitasking support.

- Integration with the native android contact list

- Speakerphone mute and hold

- UDP and TCP transports (use TCP for better battery life!)

- Supports sending of DTMF

- DNS SRV

- Built-in echo cancellation

- STUN support

- call waiting