
Description: Zulip is an open-source team chat software that focuses on threaded conversations to improve productivity and organization. It has features like public/private streams, emoji reactions, integrations, and customizable notifications.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Viber is a free messaging and calling app for smartphones. It uses your phone number to connect you with people in your contacts and allows free calls, texts, photos and video messages over WiFi.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API