Population aging leads to more expensive social security and medical care in a society. In order to minimize national expenditure dedicated to providing support to the elderly, it is necessary to reduce the cost of treatment. Current prophylactic approaches mainly include training programs tailored towards seniors, who may be assisted by caregivers, for wellness maintenance and enhancement. However, these approaches are mainly administered by volunteers, who are often overburdened because of labor shortages. It is thus necessary to design and implement a system that enables seniors to maintain and improve their health by themselves. In this study, we propose and test a smartphone-based gait measurement application. Our results indicate that the mobile application can help motivate seniors to walk more regularly and improve their walking ability. Moreover, we found in our experiments that since our application helped improve our senior subjects’ physical fitness, some of them became interested in participating in social activities and using new technologies as a consequence.