App performance tools are software applications or services that help you monitor, analyze, and optimize your app performance metrics. Firebase Performance Monitoring, New Relic Mobile, AppDynamics Mobile Real-User Monitoring, and Raygun Mobile Crash Reporting are some of the popular options that can assist in collecting and visualizing data, identifying and diagnosing problems, and implementing solutions. Firebase Performance Monitoring offers insights into your app's performance such as load time, network requests, and crashes. New Relic Mobile provides comprehensive app performance monitoring with error tracking, crash analysis, and user sessions. AppDynamics Mobile Real-User Monitoring enables you to measure and improve your app's performance, user satisfaction, and business impact. Raygun Mobile Crash Reporting is a tool that helps detect and fix app crashes, errors, and bugs.