The purpose of this research is to review the previous research on the digitization of the reflection process and the previous research on the reflection in "proactive, interactive and deep learning" in aiming at the application development for the reflection of the lesson. The method of research is an overview of 15 years of reflection research. As a result of the research, 1) it became clear that applications for reflection have already been developed and some applications are actually used. 2) these applications have four characteristics of "efficiency", "accuracy", "preservation", "sharing". In the future, it will be necessary to collect and analyze as many teachers' utterances as possible. After that, it is necessary to develop an application for reflection using the collected data and conduct experiments.
