Cartão DB is a free finance app developed by Clube Demais for Android users. With this app, you can manage your credit card easily and efficiently. It allows you to create and change your card's password, view your available balance for rotating and installment purchases, and check your invoice details, and generate a payment slip. Additionally, you can track your card usage history and purchases. The app also provides you with contact information for customer support.

Overall, Cartão DB is a useful app for those who want to keep track of their credit card expenses. Its simple interface and easy-to-use features make it accessible to all users. However, the app lacks some advanced features, such as the ability to set spending limits or receive notifications for transactions. Nevertheless, it is a handy app for basic card management tasks.