This study evaluated the use of a technology-based self-monitoring of performance (SMP) with differential reinforcement to increase task completion and reduce off-task behavior for three 5th-grade students with disabilities. A concurrent multiple baseline design across participants was used to examine the impact of the intervention on the targeted behaviors when implemented by a general education teacher and its maintenance effects with a delay of reinforcement. The implementation involved training students to use a mobile app for SMP and providing differential reinforcement contingent on task completion and accuracy of self-monitoring during academic periods. The secondary measure of off-task behavior was included to evaluate the relationship between task completion and engagement. The results demonstrated that the technology-based SMP with differential reinforcement increased task completion and reduced off-task behavior for all students. Furthermore, the gradual fading of the reinforcement, with a 45 min delay, was successful for all students. The efficiency and immediacy of the intervention suggest that technology-based SMP with differential reinforcement holds promise as a practical, efficient, and effective school-based intervention.