Background <p>Proximal femur fractures are the most common fractures in older people. Despite existing guidelines, post-operative care remains challenging. The integration of an app into rehabilitation presents a promising solution for older patients recovering from such fractures. This study aimed to develop an app-assisted rehabilitation concept for older adults after a proximal femur fracture, define the requirements for the app, and identify the prerequisites for the implementation of the concept.</p> Methods <p>The study was conducted in two phases. In the first phase, online surveys and a focus group explored key aspects of the concept’s development, structured by the Consolidated Framework for Implementation Research (CFIR). In the second phase, a think-aloud approach assessed user perspectives and interactions, with data analysed using the framework approach. This study included patients (<i>n</i> = 11) with and without prior experience using health apps, an informal caregiver (<i>n</i> = 1), as well as physical therapists (<i>n</i> = 9) and physicians with expertise in managing patients after a proximal femur fracture (<i>n</i> = 5).</p> Results <p>The proposed concept builds on inpatient rehabilitation and integrates an app offering educational content, personalized training programs, questionnaires, and tests to assess relevant treatment factors, supplemented by personal therapy sessions. Autonomy for patients in deciding whether and to what extent informal caregivers are involved in their rehabilitation was emphasized. Training for both patients and stakeholders to use the app effectively is essential. The concept primarily aims to promote patients’ independence.</p> <p>The app requirements include adaptability to geriatric patients’ physical abilities, user-friendly navigation, motivational design, compatibility with various operating systems, and credibility of content. </p> <p>Prerequisites for implementation include the cognitive and physical abilities of patients and the willingness of both patients and stakeholders to acquire skills needed for the adoption of an app-assisted concept. Organizational structures must support the concept, accompanied by a feasible remuneration framework.</p> Conclusion <p>The study resulted in the development of the PROGRES(S) concept. Successful design and implementation of this app-assisted rehabilitation concept require consideration of all CFIR dimensions. If proven feasible, acceptable, and effective, PROGRES(S) could complement existing rehabilitation programs and support patients who otherwise lack or have limited access to rehabilitation services.</p>