dspdfviewer is included in jessie-backports. Information on what
backports is and how to use it is found on backports instructions,
but to get started, try these commands (make sure to replace
deb.debian.org with your preferred debian mirror!)
As a side effect, you can now access more recent versions.
# Activate jessie-backports repository
tee -a /etc/apt/sources.list.d/jessie-backports.list <<< "deb http://deb.debian.org/debian jessie-backports main"
# ... and reload the list of available packages
apt-get update
# Install dspdfviewer
apt-get install -t jessie-backports dspdfviewer
If you already had jessie-backports activated, a
simple apt-get install dspdfviewer is enough.