MIRRA (Memory - Identity - Rights in Records – Access) is a major research project at the Department of Information Studies at University College London. Phase one (2017-2019) examined information rights in the context of child social care in England, from the perspective of care-experienced people who sought access to records of their childhoods at different stages of their lives. Findings showed strong support towards participatory recordkeeping approaches. Phase two worked with our commercial partner OLM Systems to focus on potential technology solutions. The project developed a specification for a participatory digital recordkeeping app for use in child social care settings in the UK. This document represents that specification. The MIRRA app SRS provides the technical details first, followed by an account of the interface and the features. The former is of most relevance to app developers, and the latter to potential users. The purpose of the app is to create a safe, simple way for a young person in care to record a digital personalised diary, parts of which could be shared with their social worker/ carers. Another key objective is to give the young person control, and this is done through the app via the personalisation features where customisation can be applied, and control over what is shared with their social worker. Lastly, the app uses gamification for engagement as a method to nurture and help the young person in getting the most from it.