Attention and hyperactivity disorder is one of the most frequent chronic conditions in children, which generates impulsive behaviors that cause them not to be able to concentrate properly, since they do not remember the activities that are indicated to them and, as a result, they perform poorly in school. The objective of this study is to develop a mobile application (Dilud) that allows reinforcement of the working memory of primary school children from 6 to 12 years old, through 4 interactive and dynamic games that use gamification and the cognitive training method of Tajima. To evaluate Dilud, a case study was conducted with a 6-year-old boy using the WISC version 5 test. The results of the case study show that Dilud boosts WM (working memory) by 22% making memory level pass below average. 15 children and their parents rated the app's usability and satisfaction very highly through a survey