Android - login ได้ค่า ID แล้ว แต่อยากให้ทุกคลาส Activity เรียกใช้ได้ เขียนโค้ดยังไง

public class UserHelper {
	Context context;
	SharedPreferences sharedPerfs;
	Editor editor;
	
	// Prefs Keys
	static String perfsName = "UserHelper";
	static int perfsMode = 0;
	
	public UserHelper(Context context) {
		this.context = context;
		this.sharedPerfs = this.context.getSharedPreferences(perfsName, perfsMode);
		this.editor = sharedPerfs.edit();
	}
	
	public void createSession(String key) {
		editor.putBoolean("isLogin", true);
                editor.putString("userID", key);
                editor.commit();
	}
	
	public void deleteSession() {
		editor.clear();
		editor.commit();
	}
	
	public boolean isLogin() {
		return sharedPerfs.getBoolean("isLogin", false);
	}
	
	public String getUserID() {
		return sharedPerfs.getString("userID", null);
	}
}

UserHelper usrHelper = new UserHelper(this);

// Create Session
usrHelper.createSession(ID);

// Delete Session
usrHelper.deleteSession();

// Check Login
if (usrHelper.isLogin()) {

} else {

}

// Get UserID
usrHelper.getUserID()