
Description: Secret PDF is a free software tool for Windows, Mac and Linux that allows users to password protect, encrypt and secure their PDF files. It features standard and military grade AES encryption methods to password protect and lock PDFs, preventing unauthorized access.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: QPDF is an open-source command-line tool and C++ library for manipulating and inspecting PDF files. It can split, merge, encrypt, decrypt, linearize, and fix corrupted PDF files.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API