Objective: Timely diagnosis of dementia is critical, as early identification enables interventions that improve quality of life and support long‑term planning for individuals and their families. Despite this, many Australians continue to receive a diagnosis at a late stage due to personal, social, and structural barriers. BrainTrack, a freely available, evidence‑based mobile app, was developed to help address this gap by supporting users to monitor their cognitive health and prompting earlier engagement with healthcare professionals. This study assessed the broader social and economic value generated by BrainTrack. Methods: A Social Return on Investment (SROI) framework was used to quantify outcomes associated with the app. Survey data collected 12 months after initial use captured five key impacts: increased dementia literacy, enhanced knowledge, reduced stigma, greater motivation to adopt cognitive‑health‑promoting behaviours, and increased help‑seeking intentions. Monetary values were assigned to each outcome, and inputs included development and ongoing maintenance costs. Adjustments for deadweight, displacement, attribution, and drop‑off were applied before calculating the final SROI ratio. Results: Survey responses from 2,339 users informed the analysis. With an investment of AU$1.9 million over five years, BrainTrack generated an estimated AU$7.6 million in social value, resulting in an SROI of AU$5:1. Sensitivity analyses produced ratios ranging from AU$0.86:1 to AU$24:1. The largest share of social value came from increased motivation to change, while reduced stigma and help‑seeking contributed smaller but meaningful benefits. Conclusion: Overall, BrainTrack demonstrated substantial social and economic value by promoting cognitive self‑monitoring and strengthening public understanding of dementia.