1st off, the only emulator you should be concerning yourself with is DraStic. It is the best DS emulator with the best speeds andbest compatibility.
The demo is only to test if it works with your device.
I have the Moga Pocket and DraStic and they do work together, but let me explain some things first. The Moga Pivot app the the official Moga app, and it only works with apps/games that have native Moga support. Usually the big mainstream games like Asphalt or Shadowgun. The Moga Universal Drivers App is for everything else, and you'll be needing that to work with DraStic. Moga Pivot and Moga Universal cannot work together so you'll need to switch between the two depending on what app you're using. Download and install Moga Universal, turn on Bluetooth, open the app, select your device, make sure the Moga is enabled as a keyboard/input, then select it as your virtual device, and then make sure Moga Pivot is stopped and you enable Universal. Then you'll go into DraStic options and map your controls. Keep in mind that the Moga buttons are flipped compared to the DS layout. So the Moga's Y is in the place where the DS X goes. X is Y, A is B, and B is A. Start is also Select and vise versa, but those two are less important and more of a comfort issue.
Don't forget to map your specials, they come in handy. I would ignore mapping Saving and Loading. However if you enjoy using full screen view, then mapping Flip/Swap screen to your right analog stick is an absolute must.