I only know of two options for the nm-applet.
1. Go to your main menu > Preferences > Desktop Session Settings
Remove the checkmark from Network
Log out, and log back in. The nm-applet is gone, but internet access still works. To bring it back, put the checkmark back again...log out and back in.
This works fine for a stationary computer...but less convenient for laptops that you might use in various places.
2. You could install wicd, then remove Network Manager and Network Manager Gnome.
Wicd is a little less memory hungry, but in my experience, it looks less modern (if that's important), and the Wicd applet doesn't adopt icon themes...which makes it stand out on your panel. However, you can also remove it's checkmark which will remove it from the panel, but you can easily call it up from the main menu whenever you need it. Now...I'm speaking from my experience with Debian LXDE in this regard. I can only assume it will work the same on wattOS.
If you go this route, just make sure you install wicd BEFORE you remove Network Manager and Network Manager Gnome.