What are some alternatives?
Twilio - Brings voice and messaging to your web and mobile applications.
Bitrix24 - Bitrix24 is a free (for small businesses) social enterprise platform. It is a united work space which handles the many aspects of daily operations and tasks. Create your own social intranet in minutes!
Plivo - Plivo's Voice API enables businesses to build Voice apps to reach customers globally in 200+ countries. Try Plivo's Voice API for free. Instant Sign Up.
Agile CRM - Agile CRM (Customer relationship management) features modern CRM with marketing automation, social suite & web analytics, allowing small businesses to sell and market like the Fortune 500.
Bandwidth - Track your Wi-Fi hotspot usage. Zero configuration required. It just works.
Zoho Desk - Industry's first context-aware Helpdesk Software