AppTracer is a tool that measures key mobile application metrics like load time, API response time, render time, and crashes/exceptions to help optimize quality. It monitors these metrics during both development and production. The benefits include automatic page load time calculation, comprehensive readings across different networks and devices, and quick debugging. AppTracer aggregates real-time data in a dashboard that graphically compares metrics by app version, OS, device, and network. It also provides real-time crash logs and alerts to issues that must be addressed.