Yes, competitor websites also count as 1 website credit.

For example, if you set up 3 main websites with 1 competitor website for each website that is a total of 6 domain credits.

You can always see how many credits from your plan you have used in the settings menu.

To find information on your credits:

Log in your Morningscore account
Click on the Spaceman icon in the top-right corner
Click on Settings
Click on the Subscription tab

Here's a screenshot of what you should see:

Published on: 05 / 09 / 2019