Today's increasingly rapid technological developments do not only appear in the field of communication but are also needed in education. In the education field, it is expected to instill students with adequate knowledge and critical thinking skills, which are needed for their future. Practicing critical thinking skills can be done with mobile applications because today's students are highly familiar with gadgets. In terms of education, students need a learning platform that is equipped with audio, images, and easy-to-understand text. To accommodate this, an Android-based application was designed to provide learning steps, such as analyzing, obtaining information, asking questions, and making conclusions. This study is a qualitative descriptive study using the ADDIE (analyzing, designing, developing, implementing, and evaluating) method. It includes material analysis, application design with smart apps creator (SAC), testing by media and materials experts, and overall evaluation. The trial of this application was carried out on 3rd-grade elementary school students with questionnaires and interviews. Based on the validation process by IT experts and elementary school teachers, the development of the situation-based learning (SBL) App was considered valid. In other words, this application was properly designed according to the development of lower-grade students. Furthermore, the students were interested in SBL App and found it easier to obtain information, come up with good questions, and draw conclusions from a material using the app. Therefore, it can be concluded that the SBL App developed in this study is feasible and effective to be used as an Android-based learning application to train elementary school students' critical thinking skills.