As far as I can tell, the only way to find the Code Scanner app is to use the iPhone's Spotlight search feature. Go to your iPhone's home screen and swipe down in the middle of the screen.

Epson iPrint 2.0 (for iPhone) (free), takes the app from near-zero to hero with its ease of use and a plethora of print and scan options.

Epson iPrint 2.0 (for iPhone) (free), takes the app from near-zero to hero with its ease of use and a plethora of print and scan options.