The development of a lifestyle modification mobile application, "Health for You" for overweight and obese breast cancer survivors in Korea.

Purpose: This study aimed to develop a lifestyle modification (LSM) mobile application based on the Android operating system for overweight and obese breast cancer survivors (BCS) in Korea and evaluate its usability.

Methods: The content analysis, design, development, implementation, and evaluation of the LSM intervention mobile application for overweight and obese BCS was conducted by identifying survivors' needs, searching the literature, and reviewing existing mobile applications. The survey was conducted from June 1 to December 28, 2020 at Jeonju city, Korea.

Results: The mobile application for BCS included dietary and exercise information, weight logs, as well as distress and daily achievement check. It also included information and videos on the prevention of breast cancer recurrence and used a communication bulletin board. Expert and user usability evaluation of its content and functions confirmed that it was appropriate and satisfactory for overweight and obese BCS.

Conclusion: This LSM mobile application developed for overweight and obese BCS was found to be appropriate for use. It can be applied for further study of effectiveness on improving their health and maintaining a healthy lifestyle, to ultimately improve quality of life.