new york (Bloomberg) — Travis Yates, an Australian developer of applications for Apple Inc.'s iPhone, is finding there's no such thing as bad publicity.

After Nevada's Gaming Control Board sent a memo this month to casinos warning them of Yates's Blackjack card-counting software for the iPhone, sales of the $4.99 program soared to about 500 a day, from about 10 a day in November.

Yates, whose Webtopia has created six iPhone programs sold through Apple's iTunes store, said demand for his Blackjack Card Counter picked up after he added an new features such as "Stealth Mode", where the screen shuts off while the program runs in the background. The big jump in popularity came from the Nevada Gaming Control Board's memo.

It's not that card-counting programs are inherently illegal, the Nevada Gaming Control Board said. It's unlawful to use such programs when you're at the tables, said Randall Sayre, a member of the state's Gaming Control Board and author of the February 5 memo. This is the first time the board has cautioned casinos about programs on a specific device, Sayre said.

"For every legitimate application out there, someone is thinking of how to use that application illegally," said Sayre, who has worked for the board for 30 years, including a stint as chief of investigations. "There's seldom a day that goes by that some type of arrest isn¿t made in this state of people trying to compromise a game."

Apple, which sells more than 15,000 iPhone applications through its iTunes store, declined to comment, said spokeswoman Natalie Kerris. The Cupertino, California-based company keeps 30 percent of the sales price of each application sold, and distributes free programs at no cost to developers.

Nevada heard about the iPhone program from the California Bureau of Gambling Control, which received information from a tribal casino that Sayre decline to name.

A few casinos have contacted the board requesting additional information about the program, which uses several blackjack card-counting methods to track the ratio of high cards to low cards. In blackjack, players bet against the dealer to build a hand of cards worth 21 points without going over the count.

Before the Nevada Gaming Control Board helped publicise the counting program, Webtopia's most popular iPhone applications were Army Night Vision, a 99-cent program that uses live video captured through the iPhone camera to simulate night vision goggles; and Low GI Diet, a $3.99 program that identifies foods that release glucose slowly.

To help boost sales, Yates lowered the price of the Blackjack Card Counter to $2.99 yesterday.