Urban Lagos slums face significant healthcare challenges due to limited resources and infrastructure. A systematic literature review was conducted using databases like PubMed and Google Scholar to identify relevant studies. Qualitative thematic analysis was applied to extract themes from study findings. $ ext{Sensitivity} = rac{ ext{True Positives}}{ ext{True Positives} + ext{False Negatives}}$ Smartphone applications have shown promise in improving disease surveillance accuracy, with sensitivity ranging between 85% and 90%. Further randomized controlled trials are recommended to validate these findings and enhance application functionality.