Abstract Community input into public health interventions can ensure that interventions reflect what the community wants and needs. CHESS™ (Community Health Engagement Survey Solutions) promotes community-centred prevention by engaging community members in a bottom-up investigation about their health in relation to their built environment. Using the CHESS™ application (for Android tablets), community members collect quantitative data on local assets and barriers, such as physical activity spaces and places for food shopping, that are conducive to good health (or not!). Following the mapping, community members interpret collected data during insight sessions. Personal stories are shared to provide vital context about social, economic and health inequalities. These quantitative and qualitative results inform evidence-based recommendations for interventions that make it easier to be healthy. The community then presents their recommendations to local decision-makers in a compelling argument for change. Emerging from a research project in India, China, Mexico and the United States, CHESS™ has been implemented in eight London boroughs and two United Kingdom communities. Young people, mums, and older people have participated in gathering evidence that has led to action. One borough received £150,000 from the Community Sport Activation Fund; while a north London borough was awarded over £2 million to improve physical activity opportunities for young people. Another project led to two new playgrounds co-designed with local parents. CHESS™ leverages community engagement and mobile technology to not only address the causes of chronic disease, but also issues around social justice and equity, to make the healthy option the easy option for all.