
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: Adobe Acrobat Reader is a free software application for viewing, printing, signing, and annotating PDF documents. It is the standard PDF viewer and one of the most popular free software downloads with over 2 billion installations.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API