Previously a microprocessor-based device, called Activity Analyzer with voice-Guidance for Independent Living Environments (AAGILE), was developed. The present project is focused on the implementation of AAGILE on a mobile platform that utilizes smartphone hardware such as the accelerometer and voice recording. The resulting app monitors and responds to user physical activity and inactivity; recorded voice messages will initiate to encourage exercise and/or provide instructions. This project has resulted in a cost-effective AAGILE system intended for increasing the level of activity for the older adults population.