Qoppa Software has announced PDF Studio Viewer 2018 (https://www.qoppa.com/pdfstudioviewer/), an update to their free  PDF Reader for macOS. 

Fully compliant with the new PDF 2.0 standards and Adobe PDF Specifications, the tool is designed to make PDF creation, markup, and editing easier thanks to its view tools that include the loupe, pan and zoom and more. Version 2.2 offers digital signature validation improvements, as well as bug fixes.

PDF Studio Viewer 2018 requires macOS 10.7 or higher. In addition to the free version, there’s a $129 “pro” version that adds more editing features such as content editing, OCR, optimizer, form creation, digital signatures, PDF comparison, measuring tools, imposition, permanent redaction, and preflight.