Using Rails 4.1 variants with High Voltage is simple. If you are setting variants
through your ApplicationController then variants with High Voltage will "just work".
Visit https://quiet-retreat-4814.herokuapp.com/pages/hello in your mobile, tablet, and desktop browsers for an example.
If you are looking to use variants only within your High Voltage pages, take a look at https://github.com/thoughtbot/high_voltage#override for information on how to override the default pages controller for High Voltage.
Uses browser to determine whether or not a request is coming from a mobile or tablet device.