Evaluating the Impact on Usability and Acceptance of ECAs in m-Health Applications for Older Adults Topics: e-Health and Education; Mobile Health Monitoring; Software and Applications for Independent Living; Systems to Encourage Healthy Lifestyles; Systems Usability In Proceedings of the 11th International Conference on Information and Communication Technologies for Ageing Well and e-Health ICT4AWE - Volume 1, 35-45, 2025 , Porto, Portugal