Develop a Java program that creates a simple GUI application for atemperature converter. The program should allow users to converttemperatures between Celsius and Fahrenheit.

Sure, here is a simple Java program using Swing for GUI that converts temperatures between Celsius and Fahrenheit.

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class TemperatureConverter {
    private JFrame frame;
    private JTextField textField;
    private JButton cToFButton;
    private JButton fToCButton;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    TemperatureConverter window = new TemperatureConverter();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public TemperatureConverter() {
        initialize();
    }

    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        textField = new JTextField();
        textField.setBounds(34, 36, 146, 26);
        frame.getContentPane().add(textField);
        textField.setColumns(10);

        cToFButton = new JButton("Celsius to Fahrenheit");
        cToFButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                int tempFahr = (int)((Double.parseDouble(textField.getText())) * 1.8 + 32);
                textField.setText(tempFahr + " Fahrenheit");
            }
        });
        cToFButton.setBounds(34, 89, 146, 29);
        frame.getContentPane().add(cToFButton);

        fToCButton = new JButton("Fahrenheit to Celsius");
        fToCButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                int tempCels = (int)((Double.parseDouble(textField.getText()) - 32) * 0.5556);
                textField.setText(tempCels + " Celsius");
            }
        });
        fToCButton.setBounds(34, 130, 146, 29);
        frame.getContentPane().add(fToCButton);
    }
}

This program creates a simple GUI with a text field for input and two buttons for conversion. When you enter a temperature and click a button, it converts the temperature to the other scale and displays the result in the text field.