The method of randomisation will be block randomisation (allocation ratio 1:1) which will be conducted for each of four clinical trials

Using an NHS walking app to support physical activity in older adults during NHS health-checks: a feasibility study

This study looks at whether an NHS walking app helps people over 55 who don't move much to become more active. Half the people will use the app and the other half get an exercise leaflet. It's a small study to prepare for a larger one.