A free program for Android, by Agencia Tributaria.

This is a very simple and very useful application for public administration officials to use when they want to perform some operations or tasks that require some personal information from their clients or citizens. In this case, they can send an SMS message to their mobile phone number that is associated with the application, and each time the client will be required to enter the PIN associated with the phone number in order to complete the task or operation.

This is a very simple application that can be used by public administration officials.