First thing we need ruby 2.3.0, I prefer to use rvm your mileage may vary.
rvm install 2.3.0
Now let's cd in to our project folder, and in case bundler is not installed:
gem install bundler
Once bundler is installed, it's time to install our dependencies:
bundle install
Let's setup the development and test db (it's using sqlite):
bundle exec rake db:setup
If we want to run our specs we can just:
bundle exec rspec
There is also a script to generate 300 apps in case you want to populate your development database:
bundle exec rake db:seed
Now to run the app:
bundle exec rails s
The app should be accessible through http://localhost:3000/apps