This article presents an experiment in which participant's working memory, tasks-switching and focusing skills are trained in a game called Wollie on a smartphone. Before and after the training period they performed three task (a recall, Stroop and task-switching). The goal of this research was to see how the participants, from the test group, learn within the game and how this affects the three tasks. Only in the Stroop results a clear difference between the two groups was found. However, we found that participants who had the most trouble in playing Wollie, improved the most on Stroop and task-switching, indicating that these participants still lacked the relevant skills for all these tasks.