The digital transformation of healthcare in Europe is currently undergoing a paradigm shift, moving from provider-centric systems toward a patient-oriented ecosystem mandated by the European Health Data Space regulation. While the digitalization of hospital infrastructures has been largely successful, citizens often remain passive subjects with limited control over their clinical data. This paper presents the design and implementation of a National Mobile Health Application developed as a Minimum Viable Product to bridge the gap between legislative requirements and practical citizen empowerment. The proposed solution integrates an Electronic Health Record viewer, secure medical sharing via the Verifiable Health Links protocol, and teleconsultation services within a unified, cross-platform interface. A key contribution of this work is the integration of the European Digital Identity Wallet for high-assurance authentication and the OpenNCP framework to facilitate cross-border semantic interoperability through the MyHealth@EU infrastructure. By utilizing open standards such as HL7 FHIR and CDA, the MVP demonstrates a scalable framework that enables citizens to exercise their rights to data access, portability, and insertion. Our results highlight how the synergy of these components fosters health literacy and therapeutic equity, providing a technical blueprint for National Health Authorities to comply with the EHDS and ensure that clinical data remains actionable across borders.