baresip

A baresip-based SIP app for Android supporting voice calls, text messages, voicemail, and call transfers. Features Opus, AMR, and more codecs, with TLS/WSS and ZRTP/SRTP for security. Open-source, no third-party push services. For video calls on Android 7.0+ with Camera2 API, try baresip+. Source code and issue reporting on GitHub.