
Description: STDU Viewer is a free portable software used to open and view various file types like PDFs, images, Microsoft Office documents, emails, archives, EPUB books and more. It supports viewing over 20 file formats and includes features like tabbed browsing, thumbnail previews, bookmarks and annotations.
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