Super easy fix - mtec is right. If you hold command (just as mtec said, the "apple" key) and click tab, a little submenu will undoubtably pop-up on your screen (if using a PC, the command key would be replaced by Alt).
This sub-menu will bring up a list of icons representing all of the apps you currently are running on your computer. The most recent app (the one you're currently viewing) is on the left and it descends correspondingly with the last viewed all the way to the right.
[i]Make sure[/i] N.E.D. and LE8 are your two most recently viewed apps, and simply command-tab between the two. Get used to it, and you'll be navigating a plethora of apps in mere split-seconds! I do this all the time (usually with both apps on full-screen setting). Hope this helps!!
~ Deep Deon
P.S. This is also a handy function when you have a whole bunch of apps running, and you don't want to have to look for the window containing your desired app. On Macs, the "expose" function also works well for this.