Better PDF-reader for Ubuntu called qpdfview

qpdfview PDF-reader for Ubuntu

The default PDF-reader in Ubuntu 16.04 is very plain and non-configurable, but it is easy to replace it with a better alternative, such as qpdfview, which is much more configurable.

"qpdfview is a tabbed document viewer using Poppler, libspectre, DjVuLibre, CUPS and Qt, licensed under GPL version 2 or later."
From: https://github.com/bendikro/qpdfview

Install qpdfview with this command:

sudo apt-get install qpdfview

To set qpdfview as default application for PDFs, right-click on a PDF-file, select "Properties" > "Open With", select "qpdfview and "Set as default".

In qpdfview you can configure a lot of things, for example changing the shortcuts for zooming in and out to "+" and "-", and "Fit to page size" to "z". You can do this under Edit > Settings > Shortcuts.