Yes, Card Master offers a free version with essential features, and users can also access a free trial of premium features for a limited time.

While Card Master can function offline for accessing stored cards, an internet connection is necessary for syncing data and receiving updates about offers and rewards.

Support can be reached through the app's help section, via email, or by visiting the official Card Master website where feedback forms are available for user suggestions.

You can manage or cancel your Card Master subscription through your account settings within the app, or by contacting customer support for assistance.