Mobile Vitals is a performance monitoring tool that helps mobile developers track key metrics such as cold starts, warm starts, slow frames, and frozen frames to improve their app's user experience. The tool captures distributed traces consisting of transactions and spans, providing insights into how long an app takes to start, render views, and complete HTTP requests. With auto-instrumentation, developers can easily monitor their app's performance without writing custom code. Mobile Vitals also offers graphs to explore transaction duration changes over time, slow or fastest transactions, and links related errors captured during a transaction, providing a comprehensive view into the app's performance.