AGEphone

AGEphone is a versatile SIP-based VoIP softphone designed for Android smartphones and tablets. It enables users to make high-quality voice calls using WiFi or mobile networks (including VoLTE) by simply adding their SIP provider credentials. The app supports multiple SIP providers, runs seamlessly in the background, and integrates with the device's address book and call history for unified communications.

Key features include excellent call quality, quick dialing with portraits, configurable calling rules like ringtone selection and auto-decline, voice activity detection (VAD), and support for various codecs such as G.711, GSM, G722, iLBC, SPEEX, and SILK. AGEphone also supports STUN for network traversal and multiple transport protocols like UDP and TCP. Please note that a SIP service provider is required to make calls, and usage on mobile networks may incur additional charges depending on your carrier.