Mobile Applications in Support of Contact Tracing for COVID-19: A Guidance for EU/EEA Member States [open pdf - 0B]
From the Summary: " Contact tracing is of particular significance as containment measures are lifted.  Mobile applications (apps) can help trace and alert more contacts as they do not rely on the memory of the infected case. Apps can also trace contacts unknown to the case and can notify contacts quickly and can facilitate cross-border contact tracing.  Mobile apps can complement but never replace regular contact tracing efforts. Not everyone will have a smartphone, in particular the elderly, and not everyone will have downloaded the tracing app. The use of mobile apps should be voluntary.  This document outlines several epidemiological and operational issues that public health authorities and app developers should consider.  Public health authorities should be involved in all stages of the selection, development, piloting, roll-out and evaluation of apps to ensure that they protect public health in the best way with due consideration to privacy and data protection."
2020 European Centre for Disease Prevention and Control
European Centre for Disease Prevention and Control: https://www.ecdc.europa.eu/