Don't do it. You have to install their app and use a special credit card they send you in conjunction with the app. That's how they ensure you are not cheating/sharing.

I had it for a month and then tried to cancel before my renewal; it took 3 full weeks (21 days!) of pestering their support over email every 3-5 days to escalate my refund case, and I had to threaten a BBB case before my ticket actually got escalated, and I finally got refunded 4 days after the threat. They do not have phone support at all.