
Description: Zoiper is a softphone application for making VoIP calls over the internet. It supports popular protocols like SIP, IAX, and H.323. Zoiper provides high quality audio/video calls, instant messaging, presence management and other communication features.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

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: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API