Gastroesophageal reflux disease (GERD) is a chronic condition with frequent symptom recurrence that may negatively affect sleep quality and quality of life. This randomized controlled study aims to evaluate whether a mobile application developed as a mobile application, combined with standard education and diaphragmatic breathing training, can reduce symptom recurrence and improve sleep quality and quality of life in patients with GERD. Participants will be randomly assigned to either an intervention group receiving the mobile application or a control group receiving standard education. Outcomes will be assessed using the GerdQ, Reflux Symptom Index (RSI), GERD-HRQL, and Insomnia Severity Index (ISI) at baseline, 2 weeks, 4 weeks, and 8 weeks.