In this paper we present our research that focuses on transferring design activities to third-party actors through the introduction of a design platform. While this situation is quite common and has been undertaken many times - in particular in the software industry - we study an unusual case of an innovative and successful third-party design platform: Apple's iPhone App design platform. We build upon two main streams of the recent literature on innovation: lead user innovation and toolkits for user innovation. From these main streams we deduct a model that seems to emerge from research on design and innovation that advocates for maximizing innovation openness, further supported by the more recent open innovation paradigm. We then confront our case study (Apple's iPhone App development toolkit) to the literature in order to better understand the specificity of this unusual platform. We finally propose a model based on the expertise of each actor: the firm and the third-party that is being transferred by a toolkit or a methodology. This new model enables us to better understand the differences between the two literatures and our case study, and details the concept of openness in the lead-user and the toolkits for user innovation literature. Finally we detail how Apple's toolkit transfers design capabilities and present a new model for toolkits that we call "structured empowerment".