Mitel - Business Communications and Collaboration
Skype for Slack - Move your slack discussions to a group skype call
Phonebooth - Phonebooth is one of the leading voip providers, providing phone systems & phone service for small businesses.
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