Duff, Orlaith ORCID: 0000-0002-8121-5868, Walsh, Deirdre ORCID: 0000-0003-4255-299X, Malone, Shauna ORCID: 0000-0002-7567-7935, McDermott, Lauri ORCID: 0000-0003-3271-3753, Furlong, BrĂ³na ORCID: 0000-0003-4552-0555, O'Connor, Noel E. ORCID: 0000-0002-4033-9135 and Moran, Kieran ORCID: 0000-0003-2015-8967 (2018) MedFit app, a behavior-changing, theoretically informed mobile app for patient self-management of cardiovascular disease: user-centered development. Journal of Medical Internet Research :JMIR Formative Research, 2 (1). pp. 1-22. ISSN 2561-326X