Digital health solutions and the sharing of health data promise to empower patients with information and to support them in managing their health. To address concerns about possible abuse of data, the GDPR gives citizens and patients effective control over their data. Yet, both promises, of empowerment and control, have not yet fully materialised. Individual data relevant for health remains locked in silos: the smartphone apps linked to connected medical and health devices, and the proprietary platforms and clouds where they are stored. As long as this fragmented digital ecosystem persists, it will remain difficult for patients, health professionals and researchers to aggregate it, combine it with other sources, and derive meaning. Claus, a technophile and fan of connected devices, will report from the reality of living with diabetes juggling multiple devices, and from his project to develop a truly patient-centred data platform where control of data is given back to where it belongs: the individual