Download the app from App Store, same deal may be available on all platforms.
Fantastic price. I've used this before and it has worked perfectly in Europe and US.
Great for using geo-restricted apps etc.
Once registered you can use your sign in to set up VPN on Mac and PC.
Currently many plans on sale at very low prices.
Perfect if you are going away soon or if you're a regular traveller.
I think the sale ends Sunday or Monday so be quick!