This study focuses on the development of the STEM Brain Quest mobile application tailored for senior high school students in the contemporary educational landscape. The objectives of this research are to: 1) design the user interface for three levels of difficulty—easy, intermediate, and difficult; 2) establish a database for storing questions and answers; 3) code and integrate scripts for each user interface design; and 4) evaluate the system using ISO/IEC 25010 standards. The application features three difficulty levels derived from various STEM disciplines, curated by educators with diverse expertise. Key functionalities of the system include: a) automated scoring and b) score reset for incorrect or untimely responses. A descriptive research approach was employed, with participants consisting of Grade 11 students from Adamson University, FEATI University, and the University of the East – Manila. The evaluation used ISO/IEC 25010 Software Quality Standards to measure the application’s functionality, performance, usability, and reliability, resulting in an overall very satisfactory rating. The findings indicate that the STEM Brain Quest application is highly regarded by senior high students as an effective tool for enhancing knowledge in their chosen academic tracks.