aSip (formerly known as SipPhone) is first native SIP/VoIP application. All calls are made directly to the SIP provider, no middle-man like customized proxy involved, so no voice delay and call quality is excellent
Bria for Android Tablets - Bria is a powerful VoIP softphone for Android tablets. It uses a 3G or WiFi connection to make and receive calls.
Bria offers superior audio quality with the included G.711, G.722, GSM, iLBC and SILK codecs
