Contrary to preconceived ideas, the vast majority of older people have the necessary skills to use digital tools. Although they do not like to rely solely on digital solutions, they are willing to use digital tools to enhance their lives – but have specific needs with regard to the design of such tools. This study examined the effects of the application of specific design-heuristics in the development of a social media platform on several outcome-variables in UX tests. The resulting digital tool — Resoli — helps users create and publicize new events and share memories from past ones. The tool Resoli was compared to Facebook by 26 seniors (55-85 yrs.) who conducted similar tasks on both platforms. The goal was to determine the usefulness of the developed UX design-heuristics and their influence on typical measures of UX such as perceived usability, emotional state, aesthetic, and performance measures. The results showed that participants rated Resoli significantly more positive than Facebook on all UX-indicators and showed better performance. This indicates that the use of our UX design-heuristics is meaningful and useful for this group of users.