Carrier-backed payments service Isis expanding nationwide, will work with iPhones

This post was updated at 11:18 a.m. PT to clarify that Isis will stick with NFC for payments, embedded in devices or in removable phone sleeves.
The U.S. carrier-backed Isis mobile payment service, which is still only in a couple U.S. markets, has announced two big things: it plans to expand to nationwide coverage by the end of the year and the service will work on Apple’s smartphones(s AAPL). The near-field communications-based service has so far only been accessible to Android(s GOOG) smartphones — and Apple, notably, does not make products that use NFC.
Isis is off to an extremely rocky and slow start on its mission to give mobile carriers a piece of the mobile payments pie. And in order to expand to the many smartphones that don’t have NFC chips embedded in them, the service will offer cases that are loaded with NFC chips inside that can register payments with a mobile device in physical stores.
Here’s what an Isis exec told Bloomberg, with few details about when this expansion will take place:

“What you’ll see coming from us is a vastly improved product, a variety of new places to use it, a vastly improved user experience,” Ryan Hughes, chief marketing officer at New York-based Isis, said in an interview.

The iPhone isn’t the only newcomer: the joint effort by Verizon(s VZW), AT&T(s T) and T-Mobile(s TMUS) will also work with Windows Mobile devices(s MSFT) and BlackBerry phones(s BBRY).
While Isis has slowly expanded to a couple places since its debut last fall — Austin and Salt Lake City — it says it will be available everywhere in the U.S. by the end of this year. A couple thousand businesses are currently offering it and Isis reports that there are up to 10 transactions per month per Android customer using the service.
Meanwhile, Google, which has also tried to make NFC payments happen, has been having a really hard time with its own Google Wallet service. But apps and services that have opted not to confine themselves to NFC for mobile transactions, like Square and LevelUp, have been growing.
The biggest success story has been Starbucks(s SBUX) though: it processes 3 million transactions a week in its U.S. stores. The Starbucks app, which is available on a variety of mobile platforms, including the iPhone, doesn’t use any kind of fancy payments system, which may be its best feature. All it takes is a simple barcode scanner to accept payment via preloaded gift cards.