If you've decided you want to cancel your subscription, you can do so at anytime from your Billing page. All you need to do is click your profile icon at the top of the screen, then Settings. 

On that page, click your Billing tab on the left. From there, you'll see the option to cancel your subscription.

At this time, you can not cancel from the mobile app. You'll need to login on our main website if you need to cancel.