Extension and Dissemination Core Summary The Extension and Dissemination Core (Extension) will facilitate the dissemination and expansion of all components of the MobileToolbox Research Platform, including the measure library, the technology infrastructure and the data contained in the data repository, in order to support the efforts of the cognitive research community. While the Core will assume primary responsibility for accomplishing this goal, we will work collaboratively with the other Cores and the Steering Committee to ensure success. We will provide access to the technical support, code, and components of the technology infrastructure to enable developers and clinical researchers to use the MobileToolbox platform to build a customized version of the app with desired assessments and assessment protocols to meet the needs of their study (Aim 1). The Extension Core will facilitate the dissemination of MobileToolbox data and analytic tools according to FAIR principles, the use of MobileToolbox assessments by external researchers, and the sharing of de-identified data collected by external investigators by creating and providing technical manuals, data dictionaries, manuals of procedures, answers to FAQs, training manuals and tutorials. We will support user forums via Synapse and provide direct email support with more extensive consultation available by arrangement. We will also host a website on which users can find MobileToolbox supporting documentation and links to tutorials and forums, and contact MobileToolbox staff. The Core will use a variety of methods and avenues to promote the MobileToolbox including conference and meeting presentations and exhibits, manuscript submissions, and establishing linkages to relevant government, non-profit, professional and consumer organizations and groups.