Introduction: Sensory integration and sensory diet can improve the symptoms of children with attention deficit/hyperactivity disorder (ADHD). This feasibility study aimed to evaluate the effect of using a sensory diet smartphone application by mothers on the main symptoms of their children with ADHD, including hyperactivity, attention deficit, and impulsivity. Methods: We conducted a need assessment study with the collaboration of 15 occupational therapists, developed an Android-based prototype, and evaluated it in terms of usability with the participation of 12 available mothers of children with ADHD. 12 other selected children were divided into control and experimental groups. At first, these children were evaluated using the hyperactivity subscale of the fourth version of the Pediatric Symptoms Questionnaire, and after two months of using the application by the mothers of the children in the experimental group, both groups were re-evaluated using the same questionnaire. We compared the mean score of this questionnaire before and after the mothers’ use of the application. Results: The application included 105 sensory diet exercises presented in animated format with accompanying text explanations. According to mothers' feedback, the usability of the application was rated at a high level with an average score of 8.35 out of 9. In the experimental group, attention deficit significantly improved compared to the pre-intervention stage (Mean ± SD = 13.67 ± 6.86 vs. 22 ± 6.13, P-value