NO$GBA 2.6a + NO$Zoomer - Nintendo DS emulator for PC (Size: 1.16 MB)
I tested it for a few days, works very well, with small glitches.
NO$Zoomer makes NDS games well visible, if you own a panoramic LCD with a 90' flip option you can really enjoy Dual Screen games to the fullest.
New screen filters also make graphics look a lot better.
This emu is compatible with Final Fantasy IV.
To play, run NO$Zoomer (not the emulator itself) and choose the game.