# create an etry in sources.list
sudo bash -c 'cat << EOF > /etc/apt/sources.list.d/muroa.list.test 
deb [arch=armhf] http://deb.muroa.org/raspbian jessie main
EOF

# add the signing key to your keyring
sudo bash -c 'wget -O - https:https://muroa.org/sites/default/files/martinrunge.asc | apt-key add -'

sudo apt-get update
sudo apt-get install muroad