RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Skype for Slack - Move your slack discussions to a group skype call
Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Aircall Now - Make voice calls inside Intercom Messenger 📞💬
Eir SIP Voice - eir SIP Voice is revolutionizing the core communications tool of business that carries both calls and data over just one connection.
Calls on Slack - Make voice calls in Slack