Compose Material Catalog is an Android application that serves as a canonical reference to Material Design components, theming, and dark themes. Developed by Google LLC, the app is available for free under the Utilities & Tools category.

The app consists of three main screens: the home screen, the component screen, and the example screen. Users can access the theme picker or "more" menu from the top app bar at any point. The app also supports dark themes, which is a useful feature for users who prefer a darker interface.

Overall, Compose Material Catalog is a useful tool for developers who want to learn more about Material Design components and how to implement them in Jetpack Compose. The app provides a comprehensive guide to the various components and their implementations, making it an excellent resource for developers.