Tragofone - White-label VoIP Softphone with WebRTC and Auto-provisioning
HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
PhonerLite - PhonerLite enables your PC to use it for internet telephony (VoIP , Voice over IP, SIP).
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
tSIP - tomeko.net/software: SIP client for Windows.
Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.