Create a GUI application about a system (any), e.g. library, hospital, etc., that respects the following criteria:
- By using WPF, implement an aesthetically pleasing application.
- Uses MVVM architectural pattern.
- Calls a related API, fetches and shows the data in the app.
- Connects to a database (Firebase or SQL).
Please use Visual Studio and C# to complete this project, and there is no need to connect to a real database.
Thank you in advance.