Smartphones with their rising popularity and versatile software 'apps' have great potential for revolutionising healthcare services. However, this was soon overshadowed by concerns highlighted by many studies over quality. These were subject and/or discipline specific and mostly evaluated compliance with a limited number of information portrayal standards originally devised for health websites. Hence, this study aimed to take a broader approach by evaluating the most popular apps categorised as medical in the United Kingdom for compliance with all of those standards systematically using the Health On the Net (HON) Foundation principles. The study evaluated top 50 free and paid apps of the 'medical' category on both iTunes and Google stores for evidence of compliance with an app-adapted version of the HON Foundation code of conduct. The sample included 64 apps, 34/64 (53%) were on Google Play and 36/64 (56%) were free. None of the apps managed to comply with the entire eight principles. Compliance with seven principles was achieved by only one app (1.6%), and the rest were compliant with three, two, and one (14.7%, 27%, and 38%, respectively). In conclusion, this study demonstrated that most popular apps on the medical category that are available in the United Kingdom do not meet the standards for presenting health information to the public, and this is consistent with earlier studies. Improving the situation would require raising the public awareness, providing tools that would assist in quality evaluation, encouraging developers to use robust development process, and facilitating collaboration and engagement among the stakeholders.
Keywords: Smartphones; apps; ehealth; medical apps; mobile applications; quality; quality control; quality standards.