What is a good iOS app for storing quick reference cards?

I work in EMS, and most of my coworkers and I carry around little laminated quick reference cards in our pockets or on our ID badges. I want something like this for the iPhone. Ideally, it would be a simple app that would load quickly and allow me to store images as the cards. Kind of like the Photos app, but semi-permanent and only storing 5–20 pictures total.