1. Discharged COVID-19 patients, 2. Aged from 18 to 75 years, 3. Those who have fatigue symptom, 4. Have a smart phone and can use it independently or with the help of family members, 5. Volunteer to participate in this study and sign an informed consent form.

1. Discharged COVID-19 patients, 2. Aged from 18 to 75 years, 3. Those who have fatigue symptom, 4. Have a smart phone and can use it independently or with the help of family members, 5. Volunteer to participate in this study and sign an informed consent form.