Rebel Calling alternatives

Yodel is a business phone system that allows you to make and receive calls directly inside of Slack using your existing phone numbers. Great for heavy Slack users and those that rely on inbound phone calls.

Plivo is a leading cloud communication platform that offers a simple, fast, and scalable way for companies to modernize their business communications. Companies of all types use Plivo’s API’s and SDK’s to quickly integrate voice and SMS capabilities into their applications.