Yeah, very. Once you have login details you just download the app from playstore/google play store, put your details in and you're set. There are also options in the app to load it/connect as soon as you start the box or as soon as you open the app. Changing countries or connections is easy too.
If using OpenElec or LibreElec you can use VPN Manager from Zomboided repo so that as soon as you boot up it connects automatically.
I have my account linked to apps on iPhone, Android Box, Hudl tablet, iPad and LibreElec (you get to use it on 5 devices with one subscription) and it works flawlessly on all 5. Never had any problems.