Professional programmers are significantly outnumbered by end-users of software, making it problematic to predict the diverse, dynamic needs of these users in advance. An end-user development (EUD) approach, supporting the creation and modification of software independent of professional developers, is one potential solution. EUD activities are applicable to the work practices of psychology researchers and clinicians, who increasingly rely on software for assessment of participants and patients, but must also depend on developers to realise their requirements. In practice, however, the adoption of EUD technology by these two end-user groups is contingent on various contextual factors that are not well understood. In this paper, we therefore establish recommendations for the design of EUD tools allowing non-programmers to develop apps to collect data from participants in their everyday lives, known as "experience sampling" apps. We first present interviews conducted with psychology researchers and practising clinicians on their current working practices and motivation to adopt EUD tools. We then describe our observation of a chronic disease management clinic. Finally, we describe three case studies of psychology researchers using our EUD tool Jeeves to undertake experience sampling studies, and synthesise recommendations and requirements for tools allowing the EUD of experience sampling apps. CCS Concepts: • Human-centered computing → Smartphones; Ubiquitous and mobile computing design and evaluation methods; User centered design; Field studies; • Software and its engineering → Visual languages; • Applied computing → Consumer health; Psychology.