flutter_ume
UME is an in-app debug kits platform for Flutter
...It lets developers embed a suite of debugging tools directly into a Flutter app (during development or debug builds), enabling inspection, performance monitoring, UI debugging, network request inspection, widget hierarchy introspection, and more — all from within the running app. UME bundles multiple “plugin kits” (e.g., UI inspector, performance monitor, device info panel, network inspector via Dio, console log viewer, code viewer, touch indicator) so developers can enable only the tools they need. It supports Flutter 3 and Dart with null-safety, integrates as a dev dependency (so it doesn’t ship by default with production builds), and offers a simple API to activate the debug overlay. Because it's open source under MIT license, developers can also create custom plugin kits and extend UME’s capabilities to suit their debugging or testing workflow.