Online financial management apps are increasingly popular among entrepreneurs globally, yet their adoption in female small-scale enterprises (SSEs) within informal markets remains underexplored. A mixed-method approach combining quantitative surveys and qualitative interviews was employed. Data were analysed using a linear regression model with robust standard errors to account for potential confounders. Female SSEs showed an average usage rate of 45% across apps, with significant variance in app selection based on cost-effectiveness and functionality considerations. The mixed-method approach provided nuanced insights into the challenges and opportunities faced by female SSEs in adopting financial technology solutions within informal markets. Further research should explore long-term impact of these apps on business sustainability among female entrepreneurs. Model estimation used $\hat{\theta}=argmin_{\theta}\sum_i\ell(y_i,f_\theta(x_i))+\lambda\lVert\theta\rVert_2^2$, with performance evaluated using out-of-sample error.