Description: CSipSimple is an open source SIP client for Android that allows you to make VoIP calls over Wi-Fi or mobile data. It supports common SIP features like call transfer, call forwarding, call waiting, 3-way conferencing, etc.
Type: software
Pricing: Open Source
Description: Matrix.org is an open source, decentralized communication protocol and network focused on secure and private communications. It allows users to communicate with each other on different platforms via chat, voice, video, etc.
Type: software
Pricing: Open Source