Integrating digital resources into teachers' practice requires, notably, the availability of resources offering flexibility of use (Morgan, 1990) and proximity to teachers' schemes (Crisan, Lerman, & Winbourne, 2007). Collective designing and sharing of these resources can facilitate this integration and contribute to teachers' professional development (Quéré, 2019). The e-FRAN IDEE research group work looks at the cooperation between teachers and researchers jointly designing a digital resource to teach English. The aim of this paper is to observe a part of cooperation on one teacher's professional development. In this case study, I show that the interactions between teachers in the group, Ginger and Val, lead to the discovery of new resources, and working with the latter foster new knowledge. [For the complete volume, "CALL for Widening Participation: Short Papers from EUROCALL 2020 (28th, Online, August 20-21, 2020)," see ED610330.]