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.
Tragofone - White-label VoIP Softphone with WebRTC and Auto-provisioning
ActiveCampaign - Integrated email marketing, marketing automation, and small business CRM. Send beautiful newsletters, setup behavioral based automations, and benefit from sales automation.
PhonerLite - PhonerLite enables your PC to use it for internet telephony (VoIP , Voice over IP, SIP).
Pardot - Salesforce B2B marketing automation
tSIP - tomeko.net/software: SIP client for Windows.