
Description: Viewport Sizer is a browser-based tool for testing responsive websites across various device viewports. It allows developers to see how their site looks and functions on different desktop, tablet, and mobile screens.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: zSnap is a free screenshot and annotation tool for Windows. It allows you to take screenshots, draw on them, add text and arrows, blur sensitive information, and share the annotated images. zSnap is lightweight, easy to use, and good for quickly creating explanatory screenshots.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API