A framework for planning, developing and implementing solutions with and for young people. The guidance presented in this document is intended for digital health intervention designers, developers, implementers, researchers and funders. Newcomers to digital health can use it as a start-to-finish primer on how to collaboratively and responsibly develop youth-centred digital health interventions. Those already engaged in this work can jump directly to the chapters and sections with the ideas and resources they need. Funders will find helpful advice in Annex 1, which outlines special considerations for making smarter, more meaningful investments in digital health interventions for young people.