The purpose of this document is to layout the additional work performed by Thingful to develop a user facing component that is the primary interface citizens taking part in the IoT pilot will interact with. All the previous software components developed by Thingful for the pilot are explicitly back-end server components whose only interface is the command line (when running the applications), or an HTTP based API that interacts only using Protocol Buffers or JSON. Within that context we aim to cover the following areas: The basic rationale for the component to be developed Any requirements and constraints we identified for the application Description of the proposed user journeys when using the application from onboarding with SmartCitizen to accessing collected data via the Barcelona Now dashboard. Overall system conceptual and architectural design Description of the final component as delivered to partners