Recent Chilean legislation established a curriculum focused on children with cognitive deficits, adapting the original English curriculum to a specialized one that can be used in Special Education Needs (SEN) schools. However, currently, Chilean SEN schools are not making use of these methods to support students to learn a new language such as English. Furthermore, the research of similar mobile applications available indicated a focus on native English speaking children with intellectual disabilities, however, did not support Spanish speaking children. Therefore, this study was created to observe the impact of mobile activities in English language instruction in the setting of a Chilean SEN school. The proposed solution was designed, developed, and implemented in conjunction with specialist teachers. Prototypes of the mobile application were installed on tablets specifically for this study and deployed in an experimental group. Students were assigned to two groups, control and experimental, where the same pre and post-tests were conducted. This included activities such as writing an English word from the image displayed, matching an image with the associated English word, and completing the missing letters of an English word (which was proven to be the most difficult activity). This experiment resulted in a significant impact on the learning achieved in the experimental group. The Cohen D resulted in 0.92 with a p-value of <0.001. Furthermore, the analysis of the standard deviation of time usage in each activity provided insights into the difficulty levels supporting modifications of future activities.