SPad Callkit

Spad Callkit's key features include:

- Support for different color schemes

- 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 3G and WIFI

- Multiprotocol with SIP and IAX support, compatible with all RFC

compliant PBXs

- 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 g711 (ulaw, alaw), speex, iLBC and gsm codecs

- Supports sending of DTMF

- DNS SRV

- Built-in echo cancellation

- STUN support

- Change ringtone per account

- Call waiting

- Video support

- ZRTP / TLS support

- Call Transfer

- Wideband audio