Can a smartphone app boost brain power in kids with intellectual disability?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Children aged 4-8 years (48-96 months) of both genders at the time of obtaining consent. 2. Children with borderline intellectual functioning or mild intellectual disability (FSIQ 50-85) who meet the following criteria within 3 months of screening: * Stanford-Binet Intelligence Scale - 5th edition (SB-5) criteria: FSIQ 50-85. * NIH Toolbox Cognition Battery (NIHTB-CB) DCCS score of 7 or lower. 3. Children who are capable of communicating and behaving at a level sufficient to participate in the required tests and therapeutic activities of this clinical trial. 4. Individuals for whom the legal guardian and primary caregiver have voluntarily decided to participate in this clinical trial after receiving sufficient explanation and have provided written consent to comply with the requirements of the clinical trial. Exclusion Criteria: 1. If the parents or primary caregiver of the trial subjects, who will perform the key assessments on the trial subjects, are unable to read or write in English, thus are impossible to conduct the assessments. 2. Patients with conditions (e.g., blindness, color blindness, hearing loss, or deafness) that make it difficult to perform the digital therapy of the medical device for the clinical trial, D-kit/EF1, and the key assessment item for the clinical trial, NIHTB-CB DCCS test. 3. If the subject has participated in another clinical trial or has been administered investigational drugs for clinical trial purposes within the 4 weeks prior to screening (except, cases where the subject has not received investigational drugs or has participated in non-interventional observational studies are eligible for enrollment). 4. Other subjects who are deemed unsuitable for participation in this clinical trial based on the judgment of the investigators.