Background: Efficient digitization in medicine still is in its infancy but undeniably it entails a great potential for current and future challenges in healthcare. For now, the rollout of medical apps has not resulted in a widespread use of smartphones in the German health sector. Reasons for this have not been clarified so far. Nevertheless, the lack of user involvement in the development process and content creation might contribute to the low acceptance of these products. Objective: The current study aims for outlining an approach to involve medical expertise without any coding knowledge for developing medical app content and functions. Methods: An end-user operable backend was built. Its usability was evaluated using an usability evaluation test protocol. The results of the usability tests were evaluated by the app development team and the usability test repeated for optimizing backend usability. A priori, 40 criteria to measure ease of app-usage were defined. The usability test comprised 20 tasks that had to be fulfilled. Usability tasks were analyzed for completion, drop-out and test duration. Due to the Covid-19 pandemic, digital conferences (Zoom and QuickTime Player) were applied to complete usability questionnaires. Finally, multiple backend-based apps were developed by healthcare professionals as prototypes. Results: Initial usability testing was conducted with 5 participants (4m/1w, mean age 39.2, SD 5.97 years). All of these were able to complete the given backend tasks with only a few workflow interruptions and some minor errors. After usability optimization, workflow completion time decreased from 5.03 to 3.50 minutes. The basic backend structure was clear to all test users and the handling intuitive to learn. The apps developed, using the aforementioned approach, are in clinical use as a proof of concept. Conclusions: Backends offering operability for medical professionals might pose a great potential for app development in the mHealth sector. A sophisticated and time saving usability represents the critical aspect for the acceptance of medical software. This is illustrated by multiple backend-based apps, developed by medical professionals, that are in clinical use as a proof of concept. Basic interventions are sufficient for adequate usability optimization. Practicable, well-structured software usability evaluation is possible on basis of the usability evaluation test protocol.