Fast food franchise Taco Bell has spiced up its marketing strategy with the introduction of a mobile component to its "Why Pay More" promotion.

Taco Bell launched the "Why Pay More Shaker" iPhone application, which calculates the various 79, 89 and 99 cent items on the restaurant's value menu. The application was created by the Hyperfactory.

"iPhones are considered to be the latest and the greatest," said Dave Everett, vice president and partner at KaOoga, Newton, MA. "They are made for people on the go and this fits in perfectly for fast food chains."

"The demographics also match up well as the iPhone users' age group skews towards a younger crowd," he said. "Another iPhone advantage is the enormous screen size -- an advertiser's message is impossible to miss.

"Having mobile outreach gives fast-food chains an opportunity to push new products, specials and deals."

Taco Bell first launched its Why Pay More value menu last year and it couldn't have been a more perfect time. The battered economy has taken its toll on fast-food chain sales in general and the Why Pay More value menu is a great incentive to drive sales.

The Taco Bell value menu includes a variety of menu choices including burritos, tacos and nachos.

To use the app, users just need to enter the prices of the value menu items they are buying. Then, they have to shake their phone to trigger calculation.

The application is meant to show consumers that Taco Bell is dedicated to helping consumers save money during this tough time.

The application also calculates how much change consumers are to get back.

Customers with a limited amount of money in hand can enter the amount they have and the app will show them what combinations of menu items they can afford to buy.

The app also has a store locator link that helps find the nearest Taco Bell.

"Quick service restaurants view mobile apps as a new way to engage their customers, from a simple store-finder function that helps customer find the nearest restaurant to full remote ordering and payment right from the app," said Noah N. Glass, founder CEO of Gomobo, New York.

Gomobo built an iPhone application for fast-food chain Burger King. The Burger King app lets consumer place orders and pay for them their iPhone (see story).

Additionally, Gomobo helped Subway with its mobile ordering service (see story).

"Restaurant self-service technology has evolved from in-store kiosks, to online ordering, to the mobile device," he said.