 This study aimed to design and develop a mobile application called WeChat Applet of Nutrition and Health Assessment, WANHA, which uses internet technology to better manage nutritional health for patients with malignant tumor surgery. The study found that the use of WANHA improved the nutritional health of these patients, reduced the incidence of postoperative complications, and shortened the average hospital stay. Additionally, the majority of patients and medical staff reported that they were satisfied with the app's ease of use and effectiveness. This article is authored by Yu Chih-Wu, Yu Chih-Wu, Yu Chih-Wu, and others.