The overall rating reflects the current state of the app. It accounts for all app reviews but prioritizes the most recent ones.
I installed this app because we had a regular spambot/hacker that was signing up to the newsletter 50x per week with real peoples email addresses. Both Mailchimp's recaptcha and Shopify's Google recaptcha did not do the trick. CleanTalk does! It was super easy to install, and the dashboard gives a great overview of what happened where. Yes, very satisfied, and will save me hours of manual deleting. (dont let the fact they do not have any other reviews here scare you away- in Wordpress they have many, many good reviews)