リウマチダイアリー is a lifestyle app designed to support individuals with rheumatoid arthritis. It allows users to easily record symptoms like pain, mood, temperature, cough, phlegm, and shortness of breath on their smartphones. The app automatically generates consultation reports for sharing with healthcare providers during visits, ensuring accurate communication of pain and symptoms. Users can also make quick notes about changes in their condition and track symptom variations through calendars, graphs, and tables. Additionally, the app features the "HAQ" tool to objectively assess functional impairment based on rheumatoid arthritis symptoms, along with a reminder function for upcoming clinic appointments to prevent forgetfulness.