What are some alternatives?
calibre - Ebook manager, viewer & converter
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
Adobe Acrobat Reader DC - PDF Reader, PDF Viewer
Okular - Okular is a universal document viewer based developed by KDE.
FBReader - FBReader is an e-book reader for various platforms. Features:
PDF-XChange Viewer - PDF-XChange Viewer is an alternative viewer for PDF files that enables you to view and annotate PDF...