Objectives The aim of this study was to develop a Korean version of a mood chart application on an Android platform. Methods This application is based on the traditional mood chart. Eighteen adults with DSM-5 bipolar disorder were enrolled from November 2016 to March 2017. They were asked to rate their daily mood scores and severity of irritability and impulsivity for six months. Their clinicians rated their symptom severity monthly using the Clinical Global Impression-7 (CGI-7) scale. After six months, the participants completed an anonymous questionnaire regarding their satisfaction with the application. Results Of the 18 patients, one withdrew their consent from this study and six were males (35.3%) ; their mean age was 31.71±8.56 years. The mean follow-up duration was 159.12±49.45 days and the period of application use was 143.65±52.11 days. The mean total response rate was 59.45% and the mean response rate on the same day was 43.06%. The adherence to using the application decreased significantly declined over the duration since enrollment [odds ratio (OR)=1.008, p=0.008] but tended to increase according to age (OR=0.958, p=0.002). The application mood scores were correlated significantly with the manic (β=0.307, p=0.004) and depressive (β=-0.701, p<0.001) subscale, and the total (β=1.026, p=0.002) of the CGI-7 (linear mixed models). The majority of subjects agreed that the application helped them manage their symptoms (92.86%), stating that the application was easy to use (78.57%). Conclusion This application could be a valid and useful tool to monitor the mood symptoms of patients with bipolar disorder in Korea.