Background Exercise is crucial for the well-being of people with Parkinson's disease (PD). Although there are challenges to exercising with PD, mobile apps are seen as potential solutions, though their impact is not yet fully understood. We developed a mobile app and a home-based exercise program specialised for people with PD and investigated the effect of the mobile exercise app for the people with PD. Methods Participants from the Movement Disorder Clinic were prompted to download and actively use our app for a duration of 2 weeks. Before commencing, we assessed their self-rated smartphone proficiency. Both at the start and after the 2-week period, we employed the International Physical Activity Questionnaire-Short Form and the PD Questionnaire-39 (PDQ-39) to evaluate their physical activity and overall quality of life (QoL). Exercise metrics were quantified in terms of metabolic equivalent minutes per week (MET-min/week). Furthermore, we gathered feedback on user satisfaction with the app at the end of the study. Results Out of 41 recruited patients, 25 completed the 2-week program and 16 dropped out. Median MET-min/week rose from 1386.0 to 3210.0 (P = 0.009), primarily in moderate activities (P = 0.049) and walking (P = 0.002). Median PDQ-39 scores showed improvement from 17.2 to 8.5 (P = 0.005) after the program. Conclusion The mobile app holds potential to enhance exercise and QoL for people with PD. For optimal benefits, future studies should focus on e-health literacy education, app quality enhancements, and a broader exercise program variety.