Ubuntu 12.04 Precise 64bits

Installation instructions

wget -qO- https://dl.packager.io/srv/pkgr/example-sinatra-app/key | sudo apt-key add -
sudo wget -O /etc/apt/sources.list.d/example-sinatra-app.list \
  https://dl.packager.io/srv/pkgr/example-sinatra-app/master/installer/ubuntu/12.04.repo
sudo apt-get update
sudo apt-get install example-sinatra-app

Note: You might need to apt-get install wget apt-transport-https for the above instructions to work.