
Description: CSipSimple is an open source SIP client for Android that allows you to make VoIP calls over Wi-Fi or mobile data. It supports common SIP features like call transfer, call forwarding, call waiting, 3-way conferencing, etc.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: PhonerLite is a free, open source softphone and SIP client for making VoIP calls. It supports standard SIP and RTP protocols for compatibility with most VoIP systems. PhonerLite has a simple interface and basic call features like hold, transfer, conferencing.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API