Flutter is a mobile app development framework that allows developers to build apps for multiple platforms from a single codebase. Sentry's new Flutter SDK provides a suite of tools for monitoring and maintaining apps, including device and operating system details, native crashes, session data, and version adoption. With the SDK, developers can easily segment issues, determine which users are adopting the latest versions or encountering crashes, and get notified of errors in real-time. The SDK also includes features such as offline caching and fatal crash support, allowing developers to capture valuable reports even when devices go offline or experience fatal crashes. By using Sentry's Flutter SDK, developers can focus on building great user experiences rather than debugging hard-to-find bugs.