<![CDATA[Procrastination is a barrier to the productivity of students and workers in the digital era, while conventional reminder applications tend to be passive and may experience notification delays due to push notification latency and mobile operating system power optimization policies. This study aims to design, implement, and evaluate DoYourTask, a hybrid client-server mobile reminder application integrating offline-first local notifications using exactAllowWhileIdle with gamification features, including experience points (XP), levels, badges, and leaderboards, supported by centralized server-side validation. Its motivational foundation draws on Self-Determination Theory (SDT), particularly the needs for competence and autonomy. Evaluation comprised Black Box functional testing using equivalence partitioning and boundary value analysis, RESTful API load testing with Apache Benchmark at 2, 5, and 10 virtual users (VU), MySQL query scalability testing with up to 10,000 task records, and a usability pilot study involving 10 respondents using the System Usability Scale (SUS). The results showed that all 21 functional test scenarios passed, yielding a 100% success rate. API testing achieved a 100% transaction success rate, a 0.00% error rate, and throughput of 2.75–3.29 requests per second, while median latency increased from 601 ms to 3,669 ms. The idx_users_xp composite index reduced inspected rows by 99% and improved leaderboard query performance by 26.9%. The mean SUS score was 80.5 ± 9.2, corresponding to Grade B and an Excellent rating. The results demonstrate the technical feasibility of the hybrid architecture and indicate good usability based on an initial evaluation.]]>
