Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Tragofone - White-label VoIP Softphone with WebRTC and Auto-provisioning
GEES - GEES is an all-in-one AI design platform that is shaping a future where you can brainstorm, design, hand-off in one file — without changing any other tools.
PhonerLite - PhonerLite enables your PC to use it for internet telephony (VoIP , Voice over IP, SIP).
Sketch - Professional digital design for Mac.
tSIP - tomeko.net/software: SIP client for Windows.