SmartCard is an electronic signature application developed by Validated ID that enables users to sign documents using the Spanish DNIe 3.0 (electronic national identity card) from Android smartphones equipped with NFC technology. The application provides qualified electronic signatures without requiring additional hardware beyond the smartphone and the DNIe card. The solution performs PADES-LTV (Long Term Validation) signatures that include timestamps and revocation data, ensuring document validation remains possible even after the DNIe expires. The application is designed to work with electronic identity documents from various countries and corporate smartcards that support NFC connectivity. SmartCard operates as a native application without requiring applets, enabling cryptographic card functionality directly through the smartphone. Users can sign documents both on PC and smartphone platforms using the NFC-enabled signing process. The service is accessible through the website www.firmacontudnie.es and is offered as a free application. It is part of Validated ID's VIDsigner suite of electronic signature solutions and complies with eIDAS regulations as a qualified trust service provider.