I'm so confused about this.
If you need a flashcart then what is the point of this app?
My R4i Gold flashcart works just fine for playing NDS games on my 3DS so what's this extra layer of TWLoader for?
You don't need a flashcart for this, but you can use it. The only advantage i see on it is improved VRAM and improved CPU, so i assume that some games that have framedrop on normal DS (ealier CoD; AC; Bangai-O...) will run better.