Painted during the first thirty years of the XV century, the Annunciation by the Dominican friar Giovanni da Fiesole, best known as Beato Angelico, represents the ideal intersection of the Renaissance perspective with the medieval educational value reserved to art masterpieces. This paper introduces the techniques and the procedures specifically developed to display and interactively visualize a digital replica of the Annunciation, by means of AnnunciatiOn App, a custom Real-Time Rendering application that was officially presented during the opening of the exhibition "Masaccio and Angelico. Dialogue on truth in painting", at the Museo della Basilica di Santa Maria delle Grazie in San Giovanni Valdarno, last September 2022 and still open. AnnunciatiOn App, targeted to museum visitors but also to scholars and restorers, successfully performed at the museum as a didactic kiosk hosting a 4k touch screen and a desktop computer integrated by a custom soft touch keyboard, developed by the research team.