Sipnetic

Sipnetic offers compatibility with all standards-compliant VoIP providers and PBXes, supports calling over 3G/4G and Wi-Fi, and features a modern UI with great audio quality provided by the Wideband codec. It also includes acoustic echo cancellation, automatic gain control, video calls using H.264 and VP8 codecs, and support for various NAT traversal techniques. Additionally, Sipnetic provides instant messaging with text and voice chat capabilities, secure calls based on TLS, SRTP, and ZRTP protocols, and end-to-end encryption of chat messages with OTR protocol. The app integrates with system contacts, supports presence information, and allows for multiple SIP accounts with automatic account selection. Advanced telephony features include support for multiple calls, placing calls on hold, attended transfer, sending DTMF digits, and number rewriting. Sipnetic also offers an experimental Walkie-Talkie mode, eight UI color themes, and is available in multiple languages without ads, user tracking, or personal data collection.