University student services—such as academic information access, administrative document requests, complaint handling, and campus announcements—are still largely delivered through desktop-based information systems or manual, in-person procedures, which limits accessibility for students who increasingly rely on smartphones for their daily activities. This study aims to design and evaluate a mobile-based student service application that centralizes academic and administrative services into a single platform. The application was developed using a user-centered Design Thinking approach comprising the Empathize, Define, Ideate, Prototype, and Test stages, with a high-fidelity prototype built in Figma. Usability was evaluated through task-based testing and the System Usability Scale (SUS) questionnaire administered to 30 undergraduate students. The evaluation produced a mean SUS score of 78.4, above the benchmark of 68, and an average task success rate of 93.4%, while the number of steps needed to reach any service fell from four to six page transitions in the existing portal to two taps. The discussion relates these findings to prior studies on mobile usability and technology acceptance, suggesting that simplified navigation and a clear information architecture are key contributors to user satisfaction. Practically, this research gives universities an evidence-based design reference, a low-cost evaluation protocol that can be repeated in each development iteration, and a prioritized improvement (a visible status tracker for complaints) for institutions moving student services to mobile channels.