Delirium is a neuropsychiatric syndrome which is highly prevalent among hospitalized burn patients. Among screening tools, the Intensive Care Delirium Screening Checklist (ICDSC) is a reliable tool. This study aimed to develop a mobile-based application for assessing and diagnosing delirium in burn patients by using ICDSC. This research consisted of three phases. Initially, a questionnaire was designed and users’ requirements were identified. The participants were 10 psychiatrists and 51 nurses. Then, a mobile application was designed based on the results derived from the first phase of the study and the usability of the application was evaluated by using a standard questionnaire. Finally, the rate of agreement between the nurses’ and physiatrists’ diagnoses made by using or not using the application was calculated. The application included educational content about delirium for nurses, patient data, and some functions. The results of the usability evaluation showed that the application was at a “good” level from the users’ perspectives and the rate of agreement between the nurses’ and physiatrists’ diagnoses made by using the application was higher than not using it. The application designed in the current study can help to improve the knowledge of nurses, in particular younger nurses regarding delirium. Moreover, making diagnosis based on the results of a delirium assessment tool is more accurate than relying on nursing experience. Finally, timely diagnosis of delirium can help to improve patient management and quality of care, reduce the duration of hospitalization and decrease the mortality rate and costs.