Mobile devices are everywhere, and the scope of their use is growing from simple calling and texting through Internet browsing to more technical activities such as creating message processing filters and connecting different apps. However, building tools which provide effective support for such advanced technical use of mobile devices by non-programmers (mobile end user development or mEUD) requires thorough understanding of user needs and motivations, including factors which can impact user intentions regarding mEUD activities. We propose a model linking these mEUD factors with mobile users' attitudes towards, and intent of doing mEUD, and discuss a number of implications for supporting mEUD. Our research process is user-centered, and we formulate a number of hypotheses by fusing results from an exploratory survey which gathers facts about mEUD motivations and activities, and from a focus group study, which delivers deeper understanding of particular mEUD practices and issues. We then test the hypothesized relationships through a follow-up enquiry mixing quantitative and qualitative techniques, leading to the creation of a preliminary mEUD model. Altogether we have involved 275 mobile users in our research. Our contribution links seven mEUD factors with mEUD intentions and attitudes, and highlights a number of implications for mEUD support.