But there may be other ways to tap into the more closed parts of iOS via Maps or Passbook.

ENGADGET: Switched On: iOS 6 gets back from the app

Moreover, because Passbook is part of iOS 6 this would not be limited to just iPhones and could be used on the iPod Touch and iPads.

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Much like Coupons.com, Valpak offers Passbook-integrated coupons through its iOS app.

FORBES: Apple's Passbook Hits Its Groove

When it launched with iOS 6 this Wednesday, Apple's Passbook mobile-ticketing feature boasted a handful of high-profile partners -- including Fandango, Live Nation, Lufthansa and Ticketmaster -- but that list still leaves plenty of room for fleshing out.

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All of those companies and a growing list of others now offer Passbook-integrated coupons through Coupons.com, the Coupons.com iOS application, other vendors or on their own.

FORBES: Apple's Passbook Hits Its Groove