This is a demo Flutter application that connects to a WebSocket server and allows sending and receiving messages. The application consists of a client-side Flutter app and a Node.js WebSocket server.

The server is implemented using Node.js and the 'ws' library. It listens for WebSocket connections on port 8080 and handles incoming messages from clients.

1. Install Node.js on your machine if you haven't already.
2. Navigate to the server directory: 'cd server'
3. Install the dependencies: 'npm install'
4. Start the server: 'node server.js'
5. The server will start listening for WebSocket connections on 'ws://localhost:8080'.

The client-side Flutter application allows connecting to the WebSocket server and sending/receiving messages. It utilizes the 'web_socket_channel' package for WebSocket communication and 'flutter_local_notifications' for displaying push notifications.

1. Ensure you have Flutter installed on your machine.
2. Navigate to the Flutter app directory: 'cd app'
3. Install the dependencies: 'flutter pub get'
4. Connect your device or start an emulator.
5. Run the Flutter app: 'flutter run'
6. On the app's connect screen, enter the WebSocket server URL (e.g., 'ws://localhost:8080') and click "Connect".
7. Once connected, you can send messages to the server using the input field and receive responses in real-time.

• The app sends the message to the server when the "Send" button is pressed.
• The server sends a "Hello, client!" message upon establishing a connection.
• The app receives messages from the server and displays them on the screen.
• When a message is received, the app shows a push notification with the message content.
• The app disconnects from the server when the back button is pressed.