This study investigated the effectiveness of applying a smartphone to reduce the hyperactive/impulsive behaviors of 3 students with attention deficit hyperactivity disorder (ADHD) in class. A smartphone that can simultaneously provide vibration and visual text prompts was adopted in this study to remind the participants when they exhibited hyperactive/impulsive behaviors. This study adopted the multiple baseline design across subjects under the broader rubric of the single-subject research design, including 2 baseline phases and 2 intervention phases. The results show that the time spent engaged in target behaviors decreased for participants during the intervention phases, compared to the baseline phases. The findings show that applying the vibration and visual text prompts of a smartphone is a feasible prompting strategy to assist students with ADHD to reduce their hyperactive/impulsive behaviors in class.