Tragofone - White-label VoIP Softphone with WebRTC and Auto-provisioning
Envoy - Visitor registration that's changing how guests are greeted in companies around the world.
PhonerLite - PhonerLite enables your PC to use it for internet telephony (VoIP , Voice over IP, SIP).
Teamgo - Create a safer workplace for your visitors and employees. Teamgo visitor management captures sign-ins, prints badges, sends arrival notifications and emergency alerts.
tSIP - tomeko.net/software: SIP client for Windows.
Proxyclick - Connect with Confidence