In primary education, a variety of teaching methods, such as enhanced and discovery learning, have had a significant influence on student achievement, particularly in mathematics. Several studies have discussed the positive effects of the appropriate use of technology in the classroom on student achievement. The main purpose of the current study was to determine the effects of a mobile application on student achievement in a primary school mathematics course in Saudi Arabia. Java was used in the development of the application. The study adopted a quasi-experimental design. The sample comprised 40 students from the Unaizah International School. The data collection instrument was a test in a mathematics course. The test had a reliability of >0.84. The pre- and post-test scores were analyzed with a "t"-test, which was used to examine the two null hypotheses at the 0.05 level of significance. The findings revealed that mobile applications are more effective than traditional methods for improving student outcomes in mathematics. This indicates the need for support to be provided for such activities in primary school classes. The results further indicate the effectiveness of this current application in developing students' cognitive skills and improving their mathematical abilities.