**Feasibility and Efficacy of Attentional-Control Training in Sickle Cell Disease** Sickle Cell Disease (SCD) affects the blood and can cause pain and other health problems, including trouble with thinking skills like attention. This study is testing an electronic game called EndeavorRx, which is meant to help children with attention issues. EndeavorRx is approved by the U.S. Food and Drug Administration (FDA) and is designed to challenge and improve attention skills through a fun, game-like experience. Kids aged 8-16 with SCD will use EndeavorRx on a tablet for 25-30 minutes a day, five days a week, over four weeks. The goal is to see if this program helps improve attention in kids with SCD. **Key Points:** - **Duration:** The study lasts 4 weeks with daily sessions. - **Eligibility:** Children must be 8-16 years old, diagnosed with SCD, and regularly receiving blood transfusions. - **Participation:** Children must have certain test scores that show they might benefit from attention training to join the study. This research may help improve the lives of children with SCD by enhancing their attention skills, which can be important for school and daily activities.