This guide will give you a way to download 69 roms onto your iPhone/iPod touch! Version 2.0+ is needed.
Step 1: Step One: downloading NES
First, you will need to go into the Cydia installer application. After it loads up, go to search and type in this: NES. Very simple. Scroll down to the "N's" and click on NES. Install it. The icon will look like the one in the top right corner of the picture.