3CXPhone

3CXPhone is a free VoIP Softphone application for Android supported smartphones.

3CXPhone is a SIP VoIP internet dialer designed for Android powered devices.

Features:
- Works with SIP based IP PBXs like 3CX or Asterisk;
- Works with popular VoIP providers;
- Not bound to a specific VoIP service;
- Create multiple profiles with different settings and easily switch between them.

Note: DroidX, Samsung I5700, Android 1.5 not supported.
You can download at: http://apk.cuaban.net/detail/7119/ 3CXPhone .html