One of the fundamental lessons in the Indonesian education system is the study of religion. Religious studies are very important for human life, especially to foster the feelings of students who believe more in God and shape students into noble human beings. Religion is a compulsory subject; but in public schools, the allocation of religious lessons is only 2 hours. Time allocation for this lesson is very lacking. Also, the teacher seems less attractive to most students because the way of teaching is less attractive. Another situation, using a smartphone has a negative impact on teaching. We can see that students play more smartphones for things that have nothing to do with learning. This condition further reduces students' interest in studying religion. We innovate learning using smartphones. This research aims to answer this fundamental problem. We optimize the function of mobile devices to increase interest in studying religion outside school hours. We develop mobile learning systems specifically for religious learning, using feedback learning and the latest cellular technology. We specifically design mobile applications. We divide the material into several sections according to the learning design. Each section is presented using an interesting way on the cellular interface. Students can learn and do assignments in stages as homework. On the other hand, the teacher can monitor the learning progress of each student. The teacher can motivate students through mobile facilities if needed. The teacher can also provide additional lessons individually or classically if needed. An interesting result when conducting experiments is the emergence of many student questions about religion precisely when they study at home. This shows that this method is more effective for religious studies.