
Description: Callcentric is a voice over IP (VoIP) phone service provider that offers unlimited calling plans and the ability to use your existing phones. It allows you to get a phone number in the area code of your choice and make inexpensive domestic and international calls over the internet.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: MicroSIP is an open source SIP softphone and instant messenger for making VoIP calls and sending IMs over the Internet. It supports standard SIP accounts from various providers and has features like audio/video calling, chat, presence, and more.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API