Sublime Text 2 is a great cross-platform editor for building node-webkit apps, you can download it here: http://www.sublimetext.com/2

1. Download node-webkit.app and place it in /Applications folder

2. From the Sublime Text 2 menu select Tools -> Build System -> New Build System

3. Enter the following code:

   {
       "cmd": ["nwjs", "--enable-logging", "${project_path:${file_path}}"],
       "working_dir": "${project_path:${file_path}}",
       "path": "/Applications/nwjs.app/Contents/MacOS/"
   }

Alternately use ${project_path} instead of ${project_path:${file_path}} if your package.json is in the project root directory to launch NW while viewing a file from any project sub-directory.

4. Save the configuration as nodeWebKit.sublime-build on the suggested folder
5. Open a new window in Sublime Text 2 using File -> New Window
6. Add your project to the window using Project -> Add Folder to Project...
7. Open your main application file (ex.: index.html) from the left side menu
8. Select Tools -> Build System -> nodeWebKit (required step just for Sublime Text 3)
9. Select Tools -> Build
10. At this point node-webkit application will launch with your project and you will be able to see the debugging output in Sublime Text 2

Work the same with Sublime Text 3, just notice step 8

As above, but the commands for the build system are as follows (replacing the path with the location of nw.exe):

{
    "cmd": ["nw.exe", "--enable-logging", "${project_path:${file_path}}"],
    "working_dir": "${project_path:${file_path}}",
    "path": "C:/Tools/nwjs/",
    "shell": true
}

The same process for the Mac OS, just replace the "path" with the nw path of your dist.

You can find it with which nw (return /usr/bin/nw), so in this case the nw is inside /usr/bin folder.

Example:

{
	"cmd": ["nw", "--enable-logging", "${folder}"],
	"working_dir": "${folder}",
	"path": "/usr/bin/"
}