NICE inContact - Get the DMG Consulting report reprint on cloud contact centers.
Linphone - Linphone is an internet phone or Voice Over IP phone (VoIP).
Five9 - Five9 provides cloud-based call center software for sales, marketing and support.
Zoiper - Cross-platform VoIP softphone dialer for SIP and IAX systems
Genesys PureConnect - The Genesys PureConnect platform is an all-in-one customer experience solution that’s easy to use, flexible and customizable to your business needs.
Sipdroid - Free and open-source SIP/VoIP Client