
Description: Sioyek is an open-source PDF viewer designed for reading scientific papers and academic journals. It provides advanced PDF features like synchronized dual-page view, sticky notes, highlights and annotations. Sioyek aims to offer a clutter-free interface for focused reading.
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