Unity3D Editor Tool to save Settings of GameObjects into a file. Depends on: MiniJSON(https://gist.github.com/darktable/1411710) SerializeUtility(https://gist.github.com/g0ody/5299674)

JSONTool.cs

using UnityEditor;
using UnityEngine;
using System.IO;
using System.Collections;
using System;

public class JSONTool : EditorWindow
{
    [MenuItem("Platogo/JSON Tool")]
    public static void Init()
    {
        GetWindow<JSONTool>();
    }

    public const string SETTINGS_DIR = "Assets/Settings/";
    public const string SETTINGS_TYPE = ".txt";


    private Transform target;
    private string _filename = "";
    private string[] _filenames;
    private int _index;

    void OnFocus()
    {
        Repaint();
        _filenames = GetAchievementFileNames();
    }

    void OnEnable()
    {
        _filenames = GetAchievementFileNames();
    }

    //***************************************
    // Inspector
    //***************************************

    void OnGUI()
    {
        EditorGUILayout.BeginVertical();
        EditorGUILayout.PrefixLabel("Choose Target:");
        target = EditorGUILayout.ObjectField(target, typeof(Transform), true) as Transform;

        GUI.enabled = target != null;

        EditorGUILayout.LabelField(" Clipboard:");

        EditorGUILayout.BeginHorizontal();
        if (GUILayout.Button("Save To"))
            EditorGUIUtility.systemCopyBuffer = Save();

        if (GUILayout.Button("Load From"))
            Load(EditorGUIUtility.systemCopyBuffer);
        EditorGUILayout.EndHorizontal();

        EditorGUILayout.LabelField(" File:");

        EditorGUILayout.BeginHorizontal();
        _filename = EditorGUILayout.TextField(_filename);
        if (GUILayout.Button("Save"))
            SaveToFile();
        EditorGUILayout.EndHorizontal();

        if (_filenames.Length > 0)
        {
            EditorGUILayout.BeginHorizontal();
            _index = EditorGUILayout.Popup(_index, _filenames);
            if (GUILayout.Button("Load"))
                LoadFromFile(_filenames[_index]);
            EditorGUILayout.EndHorizontal();
        }
        EditorGUILayout.EndVertical();
    }

    private void LoadFromFile(string file)
    {
        var ta = AssetDatabase.LoadAssetAtPath(SETTINGS_DIR + file + SETTINGS_TYPE, typeof(TextAsset)) as TextAsset;
        _filename = file;
        Load(ta.text);
    }

    private void Load(string json)
    {
        SerializeUtility.Deserialize(target, MiniJSON.jsonDecode(json) as Hashtable);
    }

    private void SaveToFile()
    {
        File.WriteAllText(SETTINGS_DIR + _filename + SETTINGS_TYPE, Save());
        AssetDatabase.ImportAsset(SETTINGS_DIR + _filename + SETTINGS_TYPE, ImportAssetOptions.ForceUpdate | ImportAssetOptions.ImportRecursive);
        AssetDatabase.Refresh();
        _filenames = GetAchievementFileNames();
    }

    private string Save()
    {
        return MiniJSON.jsonEncode(SerializeUtility.Serialize(target));
    }

    public static string[] GetAchievementFileNames()
    {
        if (Directory.Exists(SETTINGS_DIR))
        {
            var files = Directory.GetFiles(SETTINGS_DIR, "*" + SETTINGS_TYPE);
            files = Array.ConvertAll(files, f => f.Substring(f.LastIndexOf("/") + 1));
            files = Array.ConvertAll(files, f => f.Remove(f.Length - SETTINGS_TYPE.Length));

            var fn = new string[files.Length + 1];
            fn[0] = "None";
            files.CopyTo(fn, 1);
            return fn;
        }
        else
            return new string[0];
    }
}