Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
ApowerPDF - ApowerPDF is a versatile PDF editor which also features as PDF converter, viewer, creator and more. It provides a perfect solution for all users.
Xodo - Try easy-to-use PDF tools that keep your documents safe. Work with your important files across all platforms and devices with the ultimate all-in-one document solution. Your productivity lives at Xodo!
Icecream Apps PDF Editor - Excellent powerful tool to edit PDF, annotate PDF, redact, protect and more.
Evince - Evince is a document viewer for multiple document formats: PDF, Postscript, djvu, tiff, dvi, XPS...
Atril - Atril is a simple multi-page document viewer. Atril is a fork of Evince.