If you've got a passcode set on your iPhone, Siri and Passbook will still work by default on your Lock screen. This means that anyone who wants to talk to Siri or use one of your passes will still be able to. While it's convenient, it can be a bit unsafe. If you prefer having to use your passcode in order to use them, you can easily do so through the Settings app.
Passbook is a great way to store loyalty cards, flight information, coupons, gift cards, and members cards right on your iPhone. Many participating merchants will even scan your iPhone in order to take payment or redeem points. As long as you've got iOS 6 or higher on your iPhone, you've got Passbook.
Follow along and we'll get you set up and utilizing Passbook in no time.