http://gds-screens-slides.herokuapp.com/
It's a little Ruby / Sinatra app that gathers (and then polls) data from the GOV.UK performance platform.
Make sure you have Ruby (RVM or similar is good), Node, NPM, Grunt installed.
gem install and npm install
The server / proxy is a Ruby app. Frontend asset compilation (and the offline build) are done with Grunt.
So ruby ./server.rb and grunt will get you running locally on :4567 with sass compilation etc.
grunt offline will package up the app in a single html file. It will use yesterday's realtime data.