Network latency in mobile apps is the first and foremost concern since the majority of apps frequently fetch data from the Internet and mobile devices rely on wireless networks. To minimize network latency, we propose a novel prefetching technique which has the potential of reducing latency to “zero”. Our approach aims to prefetch latency-hogging HTTP requests in mobile applications, which enables immediate responses of the on-demand user requests. We identify the request candidates for prefetching by static analysis, rewrite the app to interact with a proxy instead of the original server, and prefetch HTTP requests based on runtime QoS constraints. A prototype is implemented for an Android app and the optimized app showed a significant latency reduction.