As per our public pricing https://clickdeploy.io/pricing.html, a free license is entitled to 10 deployment or validation attempts per month.
Our team is working on exposing these usage metrics on the UI for the upcoming releases. Hopefully, this will allow our free users to track usage easily and transparently.
Please also note that a ClickDeploy free license is intended for one single individual. If you work for a consulting firm, you should sign in ClickDeploy.io using your own organization's Salesforce account, not your client's organization.
Attempts to work around our free license limit by signing in and switching between different login accounts is considered against ClickDeploy terms of service.
Hope this provides some more details regarding our free licenses. If you have further questions, please don't hesitate to let us know.