The assessment of oral skills in the learning process of a foreign language is very important for promoting the improvement of these competences. Furthermore, digital tools can be useful for making this task easier for teachers and promoting their collaboration based on professional online communities. In this article, we present the AROSE platform, a new digital tool developed to help secondary education teachers assess their students’ oral skills in English as a foreign language. To evaluate this platform, we have promoted an international online community of secondary education teachers in a project funded by the Erasmus+ programme. The research has been developed using a design-based research methodology. Three different iterations of the platform design process were carried out. We have used a mixed method combining focus groups (of both teachers and experts), observation forms, and questionnaires for teachers. The main results obtained demonstrate the need among teachers to integrate technology to improve the evaluation process. The AROSE platform successfully caters to this need, as demonstrated by the significant data on the use and satisfaction of its users.