Checker.school is an Android application that enhances the efficiency of student attendance checking and incident recording in schools. It automates the process by scanning student cards and recording their time in and out of school. The app also keeps track of incidents and behaviors of students, which can be viewed by teachers and school staff. Moreover, it allows teachers to access the student's history with their name, time, and location, which can be viewed on their mobile phones. The app also enables the sending of circulars and notifications to teachers and parents using the Line application. Checker.school is a free application that is highly recommended for schools that need an efficient system for attendance and incident recording.