Smart SIP Phone is useful platform for Smart Dialer.
Billion Phone - compact convenient SIP phone software for making voice calls.
Enables voice connections to landline , cellular network and VoIP.
SIP Communicator - the Java VoIP and Instant Messaging client.
Fix software-related problems and remove junk files from your Lumia phone.
Configure SIP accounts, perform VoIP phone calls or initiate audio conferences.
VoIP SIP SDK provides a powerful and highly customizable solution.
Myvoipapp Sip Phone is a usefull tolls easy to use.
"VidPhone" is a H.323/SIP Video SoftPhone for Windows and Linux OS.
Net2Phone SIP Dialer lets you make phone calls using your computer.
A free SIP Softphone which offers PC-to-Phone service.
New generation phone system working in IP-networks using SIP protocol.
It enables you to make voice and video phone calls using SIP-based standards.
PortSIP Solutions, Inc.
PortGo Professional is a SIP-based phone for Windows desktop.
Frankcall provide PC to Phone, Mobile VOIP, Mobile SIP, Mobile Dialer services.
Nimbuzz - Call
Nimbuzz Phone is company's utility SIP caller for windows platform.