The General Data Protection Regulation (GDPR) requires the collection and exchange of personal data in a confidential manner. This application allows you to store two personal data files. The capital letters provide a convenient reading. On May 25, 2018, a new regulation on privacy of data in the European Union began to be applied. A seller in a store can not ask you under any circumstances for your address. If you need to issue an invoice, the billing information must be delivered by the customer on a sheet of paper received from the seller in a way that guarantees the security of the data. Thanks to an extensive use of mobile phone, the application will be very useful for many users.