Search strategy

To explore the landscape of mobile apps available for PE prescription in older adults, a systematic search was conducted in the Apple app Store and Google Play platforms using the following terms: ‘older adult’, ‘therapeutic exercise’, ‘ageing’, ‘frailty’, ‘elderly’, ‘fall risk’, ‘physical activity’ and ‘balance’.

To facilitate structured data extraction from the app stores and enable easy filtering and sorting of search results, an in-house ad hoc search tool was developed. It makes the stores searchable and produces spreadsheets containing the following information: app name; app developer; approximate number of downloads (available only in Google Play) and number of user ratings (available only in Apple app Store); average user rating; category; price; release date; corresponding URL and language (available only in Apple app Store). Our tool is not commercially available, has been only used for this research, and has been limited to extracting up to 200 of the most relevant apps for each search. The search engine allows the querying of key terms in a particular country’s app store, therefore granting access to potentially region-specific apps. This study restricted its search to the following English-speaking countries: Australia, Canada, Ireland, South Africa, United Kingdom and the United States. The search terms were used in English between the dates of 01 June 2021 and 15 June 2021.