We describe work in progress on tools and infrastructure to support adaptive component-based software for mobile devices— in our case, Apple iPhones. Our high level aim is ‘design for appropriation’, i.e. system design for uses and contexts that designers may not be able to fully predict or model in advance. Logs of users’ system operation are streamed back in real time to evaluators’ data visualisation tools, so that they can assess design problems and opportunities. Evaluators and developers can then create new software components that are sent to the mobile devices. These components are either integrated automatically on the fly, or offered as recommendations for users to accept or reject. By connecting developers, users, and evaluators, we aim to quicken the pace of iterative design so as to improve the process of creating and sustaining contextually fitting software. Categories and Subject Descriptors C.4 [Performance of Systems]: design studies, measurement techniques;...