
Description: Preview is a free and open-source document viewer application for macOS. It allows quick viewing of multiple file formats including images, PDFs, Markdown files, Office documents, and more. Preview has basic editing capabilities and annotation tools for PDFs.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: SumatraPDF is a free and open-source PDF, eBook, XPS, DjVu, CHM, Comic Book (CBZ and CBR) reader for Windows. It is lightweight, customizable, and supports many advanced PDF features.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API