Does it cost anything to use Keepthescore.com?
Some features cost extra, but the basic functionality is free.
You do not need to pay to use this app. However, paying will remove advertising from boards and unlock certain features relevant to power-users. You can read more on the pricing page.
How do I cancel my subscription?
When logged in, click on you name at the top right and then on settings. If you have an active subscription, you'll find a prominent button labelled "Cancel your subscription".