Calls on Slack - Make voice calls in Slack
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs
Rebel Calling - Internet-free international calling for $1 a month
Kixie - Better sales, made simple. Engage customers more effectively with Kixie's ultra-reliable voice & text dialer and easy automations.
Skype for Slack - Move your slack discussions to a group skype call
CloudTalk - Work locally, grow globally