Recently, Schools are collecting and keeping students' smartphones during the school day to take care of students. Therefore, the problems are arising, such as lost or stolen smartphones. If students keep smartphones themselves, they tend to use it during the class and it can disrupt class and other students. As an alternative approach to solve this problem, we can use Smartphone Control Program. With this program, we can control students' smartphones. The 'Ismartkeeper' is one of several smartphone control programs we have applied for 46 students in three schools during one semester. Then, we surveyed the effect of the 'Ismartkeeper'. As a result, since they could use their phones freely during lunch time and break time, students preferred installing the 'Ismartkeeper' program on their own smartphones to giving and getting back their phones by school. On the other hand, they said that the speed of smartphone slows down and the battery runs out fast when they use the 'Ismartkeeper' program. Therefore, they demanded that program improvement is needed