Linphone - Linphone is an internet phone or Voice Over IP phone (VoIP).
Standup Bot - An easy to use bot that automates your team’s standups, check-ins or any kind of recurring status update meetings, without breaking the bank.
Zoiper - Cross-platform VoIP softphone dialer for SIP and IAX systems
Standuply - Run daily standup meetings and track your metrics in Slack
Sipdroid - Free and open-source SIP/VoIP Client
Stork.ai - AI-Based Collaboration for Hybrid Teams. Rich media messaging, advanced video and voice conferencing, auto-transcribing and screen sharing. Serendipitous meetings at the water-cooler with your human and AI teammates.