From version Alpha 1c, it's now possible to make any shortcut button for an external app in the skin (for GPS, notepad, etc..)

Here's how to do it.

Start NSW:

Open desired skin:

Go to "Paint mode"

Paint button where you want it

Open control list and select "CUSTOM_APP" in "buttons" category

Enter name of the external app as it is (or will be) entered in NM

Button for destinator created

Open NM and create (if not allready OK) the external app shortcut. Please be sure to use the same app name as entered in NSW (in this example: destinator). In NMC, the button painted in NM will now start Destinator