are you talking about bar codes and QR codes? if so, there are many apps that will scan them. try "barcode scanner." it's free in the google play store. there's also many other apps that do it (google goggles, etc). if it's a QR code and you scan it, it will usually take you to a site with ads or offers or product information, or load a videa or something. i'm guessing that's awhat you are talking about when you say "scan here." you can also scan bar codes though, and the apps will pull up product info, or other places that carry it, etc, etc.
my bad. just realized you have an iphone so ignore my app suggestions. but the iphone's app store will have plenty of similar apps to what i described. it may even have something built in?? i'm not familiar with the iphone.