This research aims to develop Android-based learning media using a STEM approach to enhance students' problem-solving abilities. The learning media was developed using the 4D model and tested on 192 eighth-grade students from six junior high schools in Yogyakarta. The research results indicate that the developed learning media fulfills aspects of validity, practicality, and effectiveness. Validity was confirmed through assessments by subject matter experts and media experts, scoring 82 and 73.5, respectively, falling into the categories of very good and good. Practicality was established through small-scale and large-scale tests, scoring 80.27 and 76.34, respectively, categorized as good in both instances. Effectiveness was determined through effectiveness tests, including one-sample t-test and mean different test. The one-sample t-test results indicated an improvement in students' problem-solving abilities with an average increase of 21.2769 in the control class and 42.5423 in the experimental class. The conclusion drawn from this research is that Android-based learning media using a STEM approach is effective in enhancing students' problem-solving abilities.