This is a fingerprintjs2 bundled as an asset for the rails asset pipeline.
The original fingerprintjs2 is https://github.com/Valve/fingerprintjs2
Add this to your Gemfile
gem 'fingerprintjs2-rails', git:'https://github.com/mh61503891/fingerprintjs2-rails.git'
and
bundle install
After that you can add the file to sprockets:
//= require fingerprint2