Tragofone - White-label VoIP Softphone with WebRTC and Auto-provisioning

DID Logic - DID Logic is an all-in-one SIP trunk and DID numbers providing software having support for hundreds of countries with the leverage of the direct and low latency access to a regional voice carrier.

tSIP - tomeko.net/software: SIP client for Windows.

Avoxi SIP Trunking - Avoxi SIP Trunking is the advanced and professional platform for international SIP trunks that is ensuring the best voice quality, secure call routing, and dispensing cost-effective termination worldwide.

Lingo - Empower Creation and Ensure Brand Consistency. Build and Share libraries of visual assets with your entire team — all from your desktop.

Nextiva SIP Trunk - Nextiva SIP Trunk is a great utility that has been providing accessible SIP trunking numbers and providing all-important porting in an ultra-secure way.