Review of smartphone mobile applications for skin cancer detection: what are the changes in availability, functionality, and costs to users over time?

Smartphone applications (apps) are available to consumers for skin cancer prevention and early detection. This study aims to review changes over time in the skin cancer apps available to consumers as well as their functionality and costs. Apps for the prevention of skin cancer were searched on two major smartphone app stores (Android and iOS) in June 2019. The number, functionality, ratings, and price of the apps were described and compared to similar reviews of the skin cancer app market from 2014 to 2017. Overall, the June 2019 search identified 66 apps. Of 39 apps found in 2014, 30 were no longer available in 2019 representing an attrition rate of 77%; of 43 apps available in 2017, attrition was 46.5%. In 2019, 63.6% (n = 42/66) of apps were free to download compared to 53.5% (n = 23/43) in 2017. Input from clinician/professional bodies was evident for 47.0% (n = 31/66) of the apps in 2019 compared to 34.9% (15/43) in 2017. The most common app functionality offered in 2019 was monitoring/tracking of lesions at 48.5% (n = 32/66). Since 2014, there has been a steady increase in the number of apps available for the general public to support the prevention or early detection of skin cancers. There continues to be a high turnover of apps, and many apps still appear to lack clinician input and/or evidence for their safety and value.